JP7317664B2 - SUBSTRATE PROCESSING APPARATUS AND SUBSTRATE PROCESSING METHOD - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing apparatus and substrate processing method for performing predetermined processing such as heat treatment on a thin precision electronic substrate such as a semiconductor wafer (hereinafter simply referred to as "substrate").

Flash lamp annealing (FLA), which heats a semiconductor wafer in an extremely short time, has attracted attention in the manufacturing process of semiconductor devices. Flash lamp annealing uses a xenon flash lamp (hereinafter simply referred to as a "flash lamp" to mean a xenon flash lamp) to irradiate the surface of the semiconductor wafer with flash light, so that only the surface of the semiconductor wafer is extremely annealed. It is a heat treatment technology that raises the temperature in a short time (several milliseconds or less).

The radiation spectral distribution of the xenon flash lamp is from the ultraviolet region to the near-infrared region, the wavelength is shorter than that of the conventional halogen lamp, and it almost matches the fundamental absorption band of the silicon semiconductor wafer. Therefore, when the semiconductor wafer is irradiated with flash light from the xenon flash lamp, it is possible to rapidly raise the temperature of the semiconductor wafer with little transmitted light. In addition, it has been found that only the vicinity of the surface of the semiconductor wafer can be selectively heated by flash light irradiation for a very short period of several milliseconds or less.

Such flash lamp annealing is used in processes that require very short heating times, such as activation of impurities typically implanted in semiconductor wafers. By irradiating the surface of a semiconductor wafer into which impurities have been implanted by ion implantation with flash light from a flash lamp, the surface of the semiconductor wafer can be heated to the activation temperature for a very short period of time, and the impurities can be deeply diffused. Therefore, only impurity activation can be performed without causing the activation of the impurities.

Patent Document 1 discloses a flash lamp annealing apparatus in which a halogen lamp is provided on the lower side of a chamber containing a semiconductor wafer, and a flash lamp is provided on the upper side. In the apparatus disclosed in Patent Document 1, a semiconductor wafer held on a quartz susceptor in a chamber is preheated by irradiating light from a halogen lamp from below, and then flash light is emitted from a flash lamp to the surface of the semiconductor wafer. to heat the surface to a predetermined treatment temperature. Further, in the apparatus disclosed in Patent Document 1, the operation of equipment such as a halogen lamp mounted on the apparatus is controlled by a control unit.

JP 2018-49967 A

Conventionally, in substrate processing apparatuses such as the flash lamp annealing apparatus described above, when the software (OS or application) running in the control unit becomes inoperable due to runaway or the like, the inoperability is detected and controlled. A monitoring system (watchdog system) is provided to stop the However, when the control unit does not operate normally, the monitoring system also does not function normally and the operation of the equipment cannot be stopped.

For example, when the lighting of the halogen lamp is controlled by the control unit, the control is monitored by the monitoring system. will be stopped. However, if the control unit is out of control and the monitoring system does not function normally, a problem arises that the halogen lamp continues to light.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a substrate processing apparatus and a substrate processing method that can reliably stop the operation of a device to be controlled even when it becomes uncontrollable. .

In order to solve the above-mentioned problems, the invention of claim 1 provides a substrate processing apparatus for performing a predetermined process on a substrate, wherein a first control section for controlling the entire substrate processing apparatus is provided in the substrate processing apparatus, and the a plurality of controlled devices to be controlled by a first control unit; a second control unit that manages information transmission between the first control unit and some of the plurality of controlled devices; a first monitoring unit provided in a control unit for monitoring the operation of software executed by the first control unit; a second monitoring unit provided in the second control unit for monitoring the operation of the software; wherein the first monitoring unit controls the plurality of control units when the software does not receive a clear signal from a first task out of the plurality of tasks to be executed by the first control unit for a certain period of time. All of the target devices are stopped, and the second monitoring unit stops the part of the plurality of controlled devices when a clear signal is not received from a second task of the plurality of tasks for a predetermined period of time. characterized by

According to a second aspect of the present invention, there is provided a substrate processing method for performing a predetermined process on a substrate, wherein a first control unit for controlling the entire substrate processing apparatus controls a plurality of devices to be controlled provided in the substrate processing apparatus. a control step, a first monitoring step in which a first monitoring unit provided in the first control unit monitors operation of software executed by the first control unit, the first control unit and the plurality of controls a second monitoring step in which a second monitoring unit provided in a second control unit that manages information transmission with a part of the target device monitors the operation of the software ; All of the plurality of devices to be controlled when the first monitoring unit does not receive a clear signal from a first task out of the plurality of tasks to be executed by the first control unit by the software for a certain period of time and in the second monitoring step, when the second monitoring unit does not receive a clear signal from a second task of the plurality of tasks for a predetermined period of time, the part of the plurality of devices to be controlled is characterized by stopping

According to the first aspect of the present invention, a first monitoring section is provided in a first control section that controls the entire substrate processing apparatus and monitors the operation of software executed by the first control section; and a second monitoring unit that is provided in the second control unit that manages information transmission between and a part of the plurality of controlled devices and monitors the operation of the software, so that the first monitoring unit and the second monitoring unit By double-monitoring software runaway by the part of the software, even if a part of the software prevents the control target device and makes it impossible to control the control target device, the operation of the control target device can be reliably stopped. can.

According to the invention of claim 2 , the first monitoring step of monitoring the operation of the software executed by the first control unit provided in the first control unit for controlling the entire substrate processing apparatus; and a second monitoring step in which a second monitoring unit provided in a second control unit that manages information transmission between the first control unit and some of the plurality of controlled devices monitors the operation of the software. Therefore, by double-monitoring software runaway by the first monitoring unit and the second monitoring unit, even if part of the software prevents it and the control target device becomes uncontrollable, the control target device It is possible to reliably stop the operation of the device.

1 is a vertical cross-sectional view showing the configuration of a heat treatment apparatus which is an example of a substrate processing apparatus according to the present invention; FIG. It is a perspective view which shows the whole external appearance of a holding|maintenance part. 4 is a plan view of the susceptor; FIG. 4 is a cross-sectional view of the susceptor; FIG. It is a top view of a transfer mechanism. It is a side view of a transfer mechanism. FIG. 4 is a plan view showing the arrangement of a plurality of halogen lamps; It is a figure which shows the peripheral structure of a control part. It is a figure which shows the concept of several tasks which a main-control part performs.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing the configuration of a heat treatment apparatus 1, which is an example of a substrate processing apparatus according to the present invention. The heat treatment apparatus 1 of FIG. 1 is a flash lamp annealing apparatus that heats a disk-shaped semiconductor wafer W as a substrate by irradiating the semiconductor wafer W with flash light. Although the size of the semiconductor wafer W to be processed is not particularly limited, it is, for example, φ300 mm or φ450 mm (φ300 mm in this embodiment). In addition, in FIG. 1 and subsequent figures, the dimensions and numbers of each part are exaggerated or simplified as necessary for easy understanding.

The heat treatment apparatus 1 includes a chamber 6 containing a semiconductor wafer W, a flash heating section 5 containing a plurality of flash lamps FL, and a halogen heating section 4 containing a plurality of halogen lamps HL. A flash heating section 5 is provided on the upper side of the chamber 6, and a halogen heating section 4 is provided on the lower side. The heat treatment apparatus 1 also includes a holding unit 7 that holds the semiconductor wafer W in a horizontal posture inside the chamber 6, a transfer mechanism 10 that transfers the semiconductor wafer W between the holding unit 7 and the outside of the apparatus, Prepare. Further, the heat treatment apparatus 1 includes a control section 3 that controls each operation mechanism provided in the halogen heating section 4, the flash heating section 5, and the chamber 6 to perform the heat treatment of the semiconductor wafer W. As shown in FIG.

The chamber 6 is configured by mounting chamber windows made of quartz on the upper and lower sides of a cylindrical chamber side portion 61 . The chamber side part 61 has a substantially cylindrical shape with upper and lower openings, the upper opening being closed by an upper chamber window 63, and the lower opening being closed by a lower chamber window 64. ing. The upper chamber window 63 forming the ceiling of the chamber 6 is a disc-shaped member made of quartz and functions as a quartz window through which the flash light emitted from the flash heating unit 5 is transmitted into the chamber 6 . A lower chamber window 64 forming the floor of the chamber 6 is also a disk-shaped member made of quartz and functions as a quartz window through which the light from the halogen heating unit 4 is transmitted into the chamber 6 .

A reflecting ring 68 is attached to the upper portion of the inner wall surface of the chamber side portion 61, and a reflecting ring 69 is attached to the lower portion thereof. Both the reflecting rings 68 and 69 are formed in an annular shape. The upper reflector ring 68 is attached by fitting from the upper side of the chamber side 61 . On the other hand, the lower reflecting ring 69 is attached by fitting from the lower side of the chamber side portion 61 and fastening with screws (not shown). That is, both the reflecting rings 68 and 69 are detachably attached to the chamber side portion 61 . A space inside the chamber 6 , that is, a space surrounded by the upper chamber window 63 , the lower chamber window 64 , the chamber side portion 61 and the reflective rings 68 and 69 is defined as a thermal processing space 65 .

A concave portion 62 is formed in the inner wall surface of the chamber 6 by attaching the reflecting rings 68 and 69 to the chamber side portion 61 . That is, the recess 62 is formed by the central portion of the inner wall surface of the chamber side portion 61 where the reflecting rings 68 and 69 are not attached, the lower end surface of the reflecting ring 68, and the upper end surface of the reflecting ring 69. . The concave portion 62 is formed in an annular shape along the horizontal direction on the inner wall surface of the chamber 6 and surrounds the holding portion 7 that holds the semiconductor wafer W. As shown in FIG. The chamber side portion 61 and the reflecting rings 68, 69 are made of a metallic material (for example, stainless steel) having excellent strength and heat resistance.

A transfer opening (furnace port) 66 for transferring the semiconductor wafer W into and out of the chamber 6 is formed in the chamber side portion 61 . The transport opening 66 can be opened and closed by a gate valve 185 . The conveying opening 66 is communicated with the outer peripheral surface of the recess 62 . Therefore, when the gate valve 185 opens the transfer opening 66 , the semiconductor wafer W can be transferred from the transfer opening 66 to the heat treatment space 65 through the recess 62 and transferred from the heat treatment space 65 . It can be performed. Further, when the gate valve 185 closes the transfer opening 66, the heat treatment space 65 in the chamber 6 becomes a closed space.

Further, the chamber side portion 61 is provided with a through hole 61a and a through hole 61b. The through hole 61 a is a cylindrical hole for guiding infrared light emitted from the upper surface of a semiconductor wafer W held by a susceptor 74 to be described later to the infrared sensor 29 of the upper radiation thermometer 25 . On the other hand, the through hole 61b is a cylindrical hole for guiding the infrared light emitted from the lower surface of the semiconductor wafer W to the infrared sensor 24 of the lower radiation thermometer 20. As shown in FIG. The through-holes 61 a and 61 b are inclined with respect to the horizontal direction so that their through-direction axes intersect the main surface of the semiconductor wafer W held by the susceptor 74 . A transparent window 26 made of a calcium fluoride material that transmits infrared light in a wavelength range measurable by the upper radiation thermometer 25 is attached to the end of the through hole 61 a facing the heat treatment space 65 . At the end of the through hole 61b facing the heat treatment space 65, a transparent window 21 made of a barium fluoride material that transmits infrared light in a wavelength range measurable by the lower radiation thermometer 20 is mounted. .

A gas supply hole 81 for supplying a processing gas to the heat treatment space 65 is formed in the upper portion of the inner wall of the chamber 6 . The gas supply hole 81 is formed above the recess 62 and may be provided in the reflection ring 68 . The gas supply hole 81 is communicated with a gas supply pipe 83 through an annular buffer space 82 formed inside the side wall of the chamber 6 . The gas supply pipe 83 is connected to a process gas supply source 85 . A valve 84 is inserted in the middle of the path of the gas supply pipe 83 . When valve 84 is opened, process gas is delivered from process gas supply 85 to buffer space 82 . The processing gas that has flowed into the buffer space 82 flows so as to expand in the buffer space 82 having a smaller fluid resistance than the gas supply hole 81 and is supplied from the gas supply hole 81 into the heat treatment space 65 . As the processing gas, for example, an inert gas such as nitrogen (N ₂ ), a reactive gas such as hydrogen (H ₂ ) or ammonia (NH ₃ ), or a mixed gas thereof can be used (this Nitrogen gas in embodiments).

On the other hand, a gas exhaust hole 86 for exhausting the gas in the heat treatment space 65 is formed in the lower part of the inner wall of the chamber 6 . The gas exhaust hole 86 is formed below the recess 62 and may be provided in the reflecting ring 69 . The gas exhaust hole 86 is communicated with a gas exhaust pipe 88 through an annular buffer space 87 formed inside the side wall of the chamber 6 . The gas exhaust pipe 88 is connected to the exhaust section 190 . A valve 89 is inserted in the middle of the path of the gas exhaust pipe 88 . When the valve 89 is opened, the gas in the heat treatment space 65 is discharged from the gas exhaust hole 86 to the gas exhaust pipe 88 through the buffer space 87 . A plurality of gas supply holes 81 and gas exhaust holes 86 may be provided along the circumferential direction of the chamber 6, or may be slit-shaped. Further, the processing gas supply source 85 and the exhaust unit 190 may be a mechanism provided in the heat treatment apparatus 1, or may be a utility of the factory where the heat treatment apparatus 1 is installed.

A gas exhaust pipe 191 for exhausting the gas in the heat treatment space 65 is also connected to the tip of the transfer opening 66 . A gas exhaust pipe 191 is connected to an exhaust section 190 via a valve 192 . By opening the valve 192 , the gas within the chamber 6 is evacuated through the transfer opening 66 .

FIG. 2 is a perspective view showing the overall appearance of the holding portion 7. As shown in FIG. The holding portion 7 includes a base ring 71 , a connecting portion 72 and a susceptor 74 . The base ring 71, the connecting portion 72 and the susceptor 74 are all made of quartz. That is, the entire holding portion 7 is made of quartz.

The base ring 71 is an arc-shaped quartz member that is partly missing from an annular ring. This missing portion is provided to prevent interference between the transfer arm 11 of the transfer mechanism 10 and the base ring 71, which will be described later. The base ring 71 is supported by the wall surface of the chamber 6 by being placed on the bottom surface of the recess 62 (see FIG. 1). A plurality of connecting portions 72 (four in this embodiment) are erected on the upper surface of the base ring 71 along the circumferential direction of the annular shape. The connecting portion 72 is also a quartz member and is fixed to the base ring 71 by welding.

The susceptor 74 is supported by four connecting portions 72 provided on the base ring 71 . 3 is a plan view of the susceptor 74. FIG. 4 is a cross-sectional view of the susceptor 74. FIG. The susceptor 74 comprises a retaining plate 75 , a guide ring 76 and a plurality of substrate support pins 77 . The holding plate 75 is a substantially circular flat member made of quartz. The diameter of the holding plate 75 is larger than the diameter of the semiconductor wafer W. That is, the holding plate 75 has a planar size larger than the semiconductor wafer W. As shown in FIG.

A guide ring 76 is installed on the peripheral edge of the upper surface of the holding plate 75 . The guide ring 76 is an annular member having an inner diameter larger than the diameter of the semiconductor wafer W. As shown in FIG. For example, when the diameter of the semiconductor wafer W is φ300 mm, the inner diameter of the guide ring 76 is φ320 mm. The inner circumference of the guide ring 76 is tapered such that it widens upward from the holding plate 75 . The guide ring 76 is made of quartz similar to the holding plate 75 . The guide ring 76 may be welded to the upper surface of the holding plate 75, or may be fixed to the holding plate 75 by a separately processed pin or the like. Alternatively, the holding plate 75 and the guide ring 76 may be processed as an integral member.

A region of the upper surface of the holding plate 75 inside the guide ring 76 serves as a planar holding surface 75a for holding the semiconductor wafer W. As shown in FIG. A plurality of substrate support pins 77 are erected on the holding surface 75 a of the holding plate 75 . In this embodiment, a total of 12 substrate support pins 77 are erected at 30° intervals along a circle concentric with the outer circumference of the holding surface 75a (the inner circumference of the guide ring 76). The diameter of the circle in which the 12 substrate support pins 77 are arranged (the distance between the opposing substrate support pins 77) is smaller than the diameter of the semiconductor wafer W. 270 mm in shape). Each substrate support pin 77 is made of quartz. The plurality of substrate support pins 77 may be provided on the upper surface of the holding plate 75 by welding, or may be processed integrally with the holding plate 75 .

Returning to FIG. 2, the four connecting portions 72 erected on the base ring 71 and the peripheral portion of the holding plate 75 of the susceptor 74 are fixed by welding. That is, the susceptor 74 and the base ring 71 are fixedly connected by the connecting portion 72 . The holder 7 is attached to the chamber 6 by supporting the base ring 71 of the holder 7 on the wall surface of the chamber 6 . When the holding portion 7 is attached to the chamber 6, the holding plate 75 of the susceptor 74 assumes a horizontal posture (a posture in which the normal line coincides with the vertical direction). That is, the holding surface 75a of the holding plate 75 becomes a horizontal surface.

The semiconductor wafer W carried into the chamber 6 is placed and held in a horizontal posture on the susceptor 74 of the holding part 7 mounted in the chamber 6 . At this time, the semiconductor wafer W is held by the susceptor 74 while being supported by 12 substrate support pins 77 erected on the holding plate 75 . More strictly, the upper ends of the 12 substrate support pins 77 are in contact with the lower surface of the semiconductor wafer W to support the semiconductor wafer W. As shown in FIG. Since the height of the 12 substrate support pins 77 (the distance from the upper end of the substrate support pin 77 to the holding surface 75a of the holding plate 75) is uniform, the semiconductor wafer W can be horizontally positioned by the 12 substrate support pins 77. can support.

Also, the semiconductor wafer W is supported by a plurality of substrate support pins 77 at a predetermined distance from the holding surface 75a of the holding plate 75. As shown in FIG. The thickness of the guide ring 76 is greater than the height of the board support pins 77 . Accordingly, the guide ring 76 prevents the semiconductor wafer W supported by the plurality of substrate support pins 77 from being displaced in the horizontal direction.

As shown in FIGS. 2 and 3, the holding plate 75 of the susceptor 74 is formed with an opening 78 penetrating vertically. The opening 78 is provided for the lower radiation thermometer 20 to receive radiation light (infrared light) emitted from the lower surface of the semiconductor wafer W. As shown in FIG. That is, the lower radiation thermometer 20 receives the light emitted from the lower surface of the semiconductor wafer W through the transparent window 21 mounted in the opening 78 and the through hole 61b of the chamber side portion 61, and measures the temperature of the semiconductor wafer W. to measure. Further, the holding plate 75 of the susceptor 74 is formed with four through holes 79 through which the lift pins 12 of the transfer mechanism 10 (to be described later) penetrate to transfer the semiconductor wafer W. As shown in FIG.

FIG. 5 is a plan view of the transfer mechanism 10. FIG. 6 is a side view of the transfer mechanism 10. FIG. The transfer mechanism 10 includes two transfer arms 11 . The transfer arm 11 has an arc shape along the generally annular concave portion 62 . Two lift pins 12 are erected on each transfer arm 11 . The transfer arm 11 and lift pins 12 are made of quartz. Each transfer arm 11 is rotatable by a horizontal movement mechanism 13 . The horizontal movement mechanism 13 moves the pair of transfer arms 11 to the transfer operation position (solid line position in FIG. It is horizontally moved to and from the retracted position (the two-dot chain line position in FIG. 5) that does not overlap in plan view. As the horizontal movement mechanism 13, each transfer arm 11 may be rotated by an individual motor. It may be something that moves.

Also, the pair of transfer arms 11 is vertically moved together with the horizontal movement mechanism 13 by the lifting mechanism 14 . When the lifting mechanism 14 lifts the pair of transfer arms 11 to the transfer operation position, a total of four lift pins 12 pass through the through holes 79 (see FIGS. 2 and 3) drilled in the susceptor 74, and the lift pins 12 protrudes from the upper surface of the susceptor 74 . On the other hand, when the lifting mechanism 14 lowers the pair of transfer arms 11 to the transfer operation position and removes the lift pins 12 from the through-holes 79, the horizontal movement mechanism 13 moves the pair of transfer arms 11 so as to open them. The transfer arm 11 moves to the retracted position. The retracted position of the pair of transfer arms 11 is directly above the base ring 71 of the holding section 7 . Since the base ring 71 is placed on the bottom surface of the recess 62 , the retracted position of the transfer arm 11 is inside the recess 62 . An exhaust mechanism (not shown) is also provided in the vicinity of the portion where the drive section (horizontal movement mechanism 13 and lifting mechanism 14) of the transfer mechanism 10 is provided, and the atmosphere around the drive section of the transfer mechanism 10 is is discharged to the outside of the chamber 6.

Returning to FIG. 1, the flash heating unit 5 provided above the chamber 6 includes a light source composed of a plurality of (30 in this embodiment) xenon flash lamps FL inside a housing 51, and a lamp above the light source. and a reflector 52 provided to cover the . A lamp light emission window 53 is attached to the bottom of the housing 51 of the flash heating unit 5 . The lamp light emission window 53 forming the floor of the flash heating unit 5 is a plate-shaped quartz window made of quartz. By installing the flash heating unit 5 above the chamber 6 , the lamp light emission window 53 faces the upper chamber window 63 . The flash lamp FL irradiates the heat treatment space 65 with flash light from above the chamber 6 through the lamp light emission window 53 and the upper chamber window 63 .

Each of the plurality of flash lamps FL is a rod-shaped lamp having an elongated cylindrical shape, and the longitudinal direction of each flash lamp FL is along the main surface of the semiconductor wafer W held by the holding portion 7 (that is, along the horizontal direction). They are arranged in a plane so as to be parallel to each other. Therefore, the plane formed by the arrangement of the flash lamps FL is also a horizontal plane.

The xenon flash lamp FL is composed of a rod-shaped glass tube (discharge tube) in which xenon gas is filled and an anode and a cathode connected to a condenser are arranged at both ends of the tube (discharge tube), and an outer peripheral surface of the glass tube is provided. and a trigger electrode. Since xenon gas is an electrical insulator, electricity does not flow in the glass tube under normal conditions even if electric charges are accumulated in the capacitor. However, when a high voltage is applied to the trigger electrode to break down the insulation, the electricity stored in the capacitor instantly flows into the glass tube, and light is emitted by the excitation of xenon atoms or molecules at that time. In such a xenon flash lamp FL, the electrostatic energy previously stored in the capacitor is converted into an extremely short light pulse of 0.1 millisecond to 100 milliseconds. It has the characteristic of being able to irradiate extremely strong light compared to the light source. That is, the flash lamp FL is a pulsed light emitting lamp that instantaneously emits light in an extremely short time of less than 1 second. The light emission time of the flash lamp FL can be adjusted by the coil constant of the lamp power source that supplies power to the flash lamp FL.

Moreover, the reflector 52 is provided above the plurality of flash lamps FL so as to cover them as a whole. The basic function of the reflector 52 is to reflect the flash light emitted from the plurality of flash lamps FL to the heat treatment space 65 side. The reflector 52 is made of an aluminum alloy plate, and its surface (the surface facing the flash lamp FL) is roughened by blasting.

The halogen heating unit 4 provided below the chamber 6 incorporates a plurality of (40 in this embodiment) halogen lamps HL inside a housing 41 . The halogen heating unit 4 heats the semiconductor wafer W by irradiating the heat treatment space 65 with light from the lower side of the chamber 6 through the lower chamber window 64 using a plurality of halogen lamps HL.

FIG. 7 is a plan view showing the arrangement of multiple halogen lamps HL. The 40 halogen lamps HL are arranged in two upper and lower stages. Twenty halogen lamps HL are arranged in the upper stage near the holding part 7, and twenty halogen lamps HL are arranged in the lower stage farther from the holding part 7 than the upper stage. Each halogen lamp HL is a rod-shaped lamp having an elongated cylindrical shape. The 20 halogen lamps HL in both the upper stage and the lower stage are arranged such that their longitudinal directions are parallel to each other along the main surface of the semiconductor wafer W held by the holding portion 7 (that is, along the horizontal direction). there is Therefore, the plane formed by the arrangement of the halogen lamps HL in both the upper stage and the lower stage is a horizontal plane.

Further, as shown in FIG. 7, the density of the halogen lamps HL in both the upper stage and the lower stage is higher in the area facing the peripheral portion than in the area facing the central portion of the semiconductor wafer W held by the holding portion 7. there is That is, in both the upper and lower stages, the arrangement pitch of the halogen lamps HL is shorter in the peripheral portion than in the central portion of the lamp arrangement. Therefore, it is possible to irradiate a larger amount of light to the peripheral portion of the semiconductor wafer W, which tends to cause a temperature drop during heating by light irradiation from the halogen heating unit 4 .

A group of halogen lamps HL in the upper stage and a group of halogen lamps HL in the lower stage are arranged so as to cross each other in a grid pattern. That is, a total of 40 halogen lamps HL are arranged such that the longitudinal direction of the 20 halogen lamps HL arranged in the upper stage and the longitudinal direction of the 20 halogen lamps HL arranged in the lower stage are perpendicular to each other. there is

The halogen lamp HL is a filament-type light source that emits light by turning the filament incandescent by energizing the filament arranged inside the glass tube. Inside the glass tube, a gas obtained by introducing a small amount of a halogen element (iodine, bromine, etc.) into an inert gas such as nitrogen or argon is sealed. By introducing a halogen element, it becomes possible to set the temperature of the filament to a high temperature while suppressing breakage of the filament. Therefore, the halogen lamp HL has characteristics that it has a longer life than a normal incandescent lamp and can continuously irradiate strong light. That is, the halogen lamp HL is a continuous lighting lamp that continuously emits light for at least one second. Further, since the halogen lamp HL is a rod-shaped lamp, it has a long life. By arranging the halogen lamp HL along the horizontal direction, the radiation efficiency to the semiconductor wafer W above is excellent.

In addition, a reflector 43 is provided below the two-stage halogen lamp HL in the housing 41 of the halogen heating unit 4 (FIG. 1). The reflector 43 reflects the light emitted from the plurality of halogen lamps HL to the heat treatment space 65 side.

As shown in FIG. 1, the chamber 6 is provided with two radiation thermometers (pyrometers in this embodiment), an upper radiation thermometer 25 and a lower radiation thermometer 20 . The upper radiation thermometer 25 is installed obliquely above the semiconductor wafer W held by the susceptor 74 and receives infrared light emitted from the upper surface of the semiconductor wafer W to measure the temperature of the upper surface. The infrared sensor 29 of the upper radiation thermometer 25 is provided with an InSb (indium antimonide) optical element so as to cope with a sudden temperature change of the upper surface of the semiconductor wafer W at the moment when the flash light is irradiated. On the other hand, the lower radiation thermometer 20 is provided obliquely below the semiconductor wafer W held by the susceptor 74 and receives infrared light emitted from the lower surface of the semiconductor wafer W to measure the temperature of the lower surface.

The control unit 3 controls the various operating mechanisms provided in the heat treatment apparatus 1 . FIG. 8 is a diagram showing the peripheral configuration of the control unit 3. As shown in FIG. The controller 3 includes a main controller (first controller) 31 . The main control unit 31 controls the heat treatment apparatus 1 as a whole. That is, the lamp power supply for supplying power to the halogen lamp HL and the bulbs 84 and 89 are control target devices to be controlled by the main control unit 31 . The main control unit 31 has a hardware configuration similar to that of a general computer, and includes a CPU (not shown) that is a circuit that performs various arithmetic processing.

The control unit 3 also includes an input/output control unit (second control unit) 32 . The input/output control unit 32 manages information transmission between some of the plurality of devices to be controlled mounted in the heat treatment apparatus 1 and the main control unit 31 . The input/output control unit 32 is connected to a slave unit 35 by a line, and the slave unit 35 is connected to a plurality of devices to be controlled including the lamp power source 49 of the halogen lamp HL and the bulbs 84 and 89 . The input/output control unit 32 manages input/output of information to/from a plurality of devices to be controlled such as the lamp power source 49 . The main control unit 31 transmits and receives information to and from a plurality of controlled devices such as the lamp power source 49 via the input/output control unit 32, thereby controlling the controlled devices.

The main control unit 31 controls a plurality of devices to be controlled by the CPU executing predetermined software (including an OS and applications). In this embodiment, the main control unit 31 is provided with a first monitoring unit 36 and the input/output control unit 32 is provided with a second monitoring unit 37 . Both the first monitoring unit 36 and the second monitoring unit 37 comprise a so-called watchdog system. That is, the first monitoring unit 36 has a timer (watchdog timer), and when it does not receive a clear signal from the software executed by the main control unit 31 for a certain period of time, Stop the operation of all controlled devices. The second monitoring unit 37 also has a timer, and detects the controlled object connected to the input/output control unit 32 when the clear signal is not received from the software executed by the main control unit 31 for a certain period of time. Stop the operation of the equipment. The operations of the first monitoring section 36 and the second monitoring section 37 will be further described later.

A liquid crystal touch panel 33 is connected to the control unit 3 . The touch panel 33 displays various information and accepts input of various comments and parameters. That is, the touch panel 33 functions as a GUI (Graphical User Interface) having both functions of a display section and an input section. An operator of the heat treatment apparatus 1 can input commands and parameters from the touch panel 33 while confirming information displayed on the touch panel 33 . Instead of the touch panel 33, a combination of an input unit such as a keyboard or mouse and a display unit such as a liquid crystal display may be used.

In addition to the above configuration, the heat treatment apparatus 1 prevents excessive temperature rise of the halogen heating section 4, the flash heating section 5, and the chamber 6 due to thermal energy generated from the halogen lamps HL and the flash lamps FL during the heat treatment of the semiconductor wafer W. Therefore, it has various cooling structures. For example, the walls of the chamber 6 are provided with water cooling pipes (not shown). The halogen heating unit 4 and the flash heating unit 5 have an air-cooling structure in which heat is exhausted by forming a gas flow inside. Air is also supplied to the gap between the upper chamber window 63 and the lamp light emission window 53 to cool the flash heating part 5 and the upper chamber window 63 .

Next, processing operations in the heat treatment apparatus 1 will be described. First, a heat treatment operation for a normal semiconductor wafer (product wafer) W as a product will be described. The processing procedure of the semiconductor wafer W described below proceeds as the main control section 31 of the control section 3 controls each operating mechanism of the heat treatment apparatus 1 .

First, prior to the processing of the semiconductor wafer W, the valve 84 for supplying air is opened, and the valve 89 for exhausting is opened to start supplying and exhausting the inside of the chamber 6 . When the valve 84 is opened, nitrogen gas is supplied from the gas supply hole 81 to the heat treatment space 65 . Further, when the valve 89 is opened, the gas inside the chamber 6 is exhausted from the gas exhaust hole 86 . As a result, the nitrogen gas supplied from the upper portion of the heat treatment space 65 inside the chamber 6 flows downward and is exhausted from the lower portion of the heat treatment space 65 .

Further, the gas in the chamber 6 is exhausted from the transfer opening 66 by opening the valve 192 . Furthermore, the atmosphere around the drive section of the transfer mechanism 10 is also exhausted by an exhaust mechanism (not shown). Nitrogen gas is continuously supplied to the heat treatment space 65 during the heat treatment of the semiconductor wafer W in the heat treatment apparatus 1, and the supply amount is appropriately changed according to the treatment process.

Subsequently, the gate valve 185 is opened to open the transfer opening 66 , and the semiconductor wafer W to be processed is carried into the heat treatment space 65 in the chamber 6 through the transfer opening 66 by the transfer robot outside the apparatus. At this time, there is a risk that the atmosphere outside the apparatus will be involved as the semiconductor wafer W is loaded. Involvement of the external atmosphere can be minimized.

The semiconductor wafer W carried in by the transfer robot advances to a position directly above the holding part 7 and stops there. When the pair of transfer arms 11 of the transfer mechanism 10 moves horizontally from the retracted position to the transfer operation position and rises, the lift pins 12 protrude from the upper surface of the holding plate 75 of the susceptor 74 through the through holes 79 . receives the semiconductor wafer W. At this time, the lift pins 12 rise above the upper ends of the substrate support pins 77 .

After the semiconductor wafer W is placed on the lift pins 12 , the transfer robot leaves the heat treatment space 65 and the transfer opening 66 is closed by the gate valve 185 . As the pair of transfer arms 11 descends, the semiconductor wafer W is transferred from the transfer mechanism 10 to the susceptor 74 of the holding section 7 and held from below in a horizontal posture. The semiconductor wafer W is held by the susceptor 74 while being supported by a plurality of substrate support pins 77 erected on a holding plate 75 . The semiconductor wafer W is held by the holding portion 7 with the surface to be processed facing upward. A predetermined gap is formed between the back surface (main surface opposite to the front surface) of the semiconductor wafer W supported by the plurality of substrate support pins 77 and the holding surface 75 a of the holding plate 75 . The pair of transfer arms 11 that have descended below the susceptor 74 are retracted by the horizontal movement mechanism 13 to the retracted position, that is, to the inside of the recess 62 .

After the semiconductor wafer W is held from below in a horizontal posture by the susceptor 74 of the holding unit 7 made of quartz, the 40 halogen lamps HL of the halogen heating unit 4 are lit all at once to perform preheating (assist heating). ) is started. Halogen light emitted from the halogen lamps HL passes through the lower chamber window 64 and the susceptor 74 made of quartz, and irradiates the lower surface of the semiconductor wafer W. As shown in FIG. The semiconductor wafer W is preheated by being irradiated with light from the halogen lamp HL, and the temperature rises. Since the transfer arm 11 of the transfer mechanism 10 is retracted inside the recess 62, it does not interfere with the heating by the halogen lamp HL.

A lower radiation thermometer 20 measures the temperature of the semiconductor wafer W, which is heated by light irradiation from the halogen lamps HL. The measured temperature of the semiconductor wafer W is transmitted to the controller 3 . The main control unit 31 of the control unit 3 controls the output of the halogen lamps HL while monitoring whether the temperature of the semiconductor wafer W, which is heated by light irradiation from the halogen lamps HL, has reached a predetermined preheating temperature T1. Control. That is, the main controller 31 feedback-controls the output of the halogen lamp HL based on the measured value by the lower radiation thermometer 20 so that the temperature of the semiconductor wafer W reaches the preheating temperature T1.

After the temperature of the semiconductor wafer W reaches the preheating temperature T1, the main controller 31 temporarily maintains the semiconductor wafer W at the preheating temperature T1. Specifically, when the temperature of the semiconductor wafer W measured by the lower radiation thermometer 20 reaches the preheating temperature T1, the main controller 31 adjusts the output of the halogen lamp HL to increase the temperature of the semiconductor wafer W. It is maintained at approximately the preheating temperature T1.

By performing such preheating using the halogen lamps HL, the temperature of the entire semiconductor wafer W is uniformly raised to the preheating temperature T1. In the stage of preheating by the halogen lamps HL, the temperature of the peripheral portion of the semiconductor wafer W, where heat is more likely to be released, tends to be lower than that of the central portion. The region facing the peripheral portion of the semiconductor wafer W is higher than the region facing the central portion. For this reason, the amount of light irradiated to the peripheral portion of the semiconductor wafer W, which tends to cause heat dissipation, is increased, and the in-plane temperature distribution of the semiconductor wafer W in the preheating stage can be made uniform.

When a predetermined time has elapsed since the temperature of the semiconductor wafer W reached the preheating temperature T1, the flash lamps FL of the flash heating unit 5 irradiate the surface of the semiconductor wafer W held by the susceptor 74 with flash light. At this time, part of the flash light emitted from the flash lamp FL goes directly into the chamber 6, and the other part is once reflected by the reflector 52 and then goes into the chamber 6. Flash heating of the semiconductor wafer W is effected by irradiation.

Since the flash heating is performed by irradiating flash light (flash light) from the flash lamps FL, the surface temperature of the semiconductor wafer W can be raised in a short time. That is, the flash light emitted from the flash lamp FL has an extremely short irradiation time of about 0.1 millisecond or more and 100 millisecond or less, in which the electrostatic energy previously stored in the capacitor is converted into an extremely short light pulse. A strong flash. Then, the surface temperature of the semiconductor wafer W flash-heated by flash light irradiation from the flash lamps FL instantaneously rises to the processing temperature T2 of 1000° C. or higher, and then rapidly drops.

The halogen lamp HL is extinguished after a predetermined time has elapsed after the flash heating process is completed. As a result, the temperature of the semiconductor wafer W is rapidly lowered from the preheating temperature T1. The temperature of the semiconductor wafer W during cooling is measured by the lower radiation thermometer 20 , and the measurement result is transmitted to the controller 3 . The main control section 31 of the control section 3 monitors whether the temperature of the semiconductor wafer W has decreased to a predetermined temperature based on the measurement result of the lower radiation thermometer 20 . After the temperature of the semiconductor wafer W is lowered to a predetermined level or less, the pair of transfer arms 11 of the transfer mechanism 10 moves horizontally again from the retracted position to the transfer operation position, thereby moving the lift pins 12 to the susceptor. It protrudes from the upper surface of 74 and receives the semiconductor wafer W after heat treatment from the susceptor 74 . Subsequently, the transfer opening 66 closed by the gate valve 185 is opened, the semiconductor wafer W placed on the lift pins 12 is transferred out of the chamber 6 by the transfer robot outside the apparatus, and the semiconductor wafer W is heat-treated. complete.

A series of processes for the semiconductor wafer W as described above is performed by the main control section 31 of the control section 3 controlling a plurality of devices to be controlled such as the lamp power supply 49 mounted on the heat treatment apparatus 1 . The main control unit 31 controls a plurality of devices to be controlled by the CPU of the main control unit 31 executing predetermined software. Here, when the main control unit 31 executes predetermined software, the CPU is time-divided to sequentially execute a plurality of tasks (processes).

FIG. 9 is a diagram showing the concept of multiple tasks executed by the main control unit 31. As shown in FIG. In the figure, the horizontal axis is the time axis. In the example of FIG. 9, the main controller 31 sequentially and repeatedly executes five tasks when the semiconductor wafer W is processed in the heat treatment apparatus 1 . The time during which the main control unit 31 is executing one task is extremely short. A first task 91 of the five tasks executed by the main control unit 31 is a task related to overall management of the heat treatment apparatus 1 . A second task 92 among the five tasks is a task related to input/output to/from a plurality of control target devices.

While the software is operating normally in the main control unit 31, the clear signal is transmitted from the first task 91 to the first monitoring unit 36 while the main control unit 31 is executing the first task 91. be done. Upon receiving the clear signal from the first task 91, the first monitoring unit 36 resets the timer and restarts counting of the timer. While the software is operating normally, the clear signal is repeatedly transmitted from the first task 91 to the first monitoring unit 36 at regular intervals, and the count of the timer of the first monitoring unit 36 is reset each time. It will be done. The first monitoring unit 36 determines that the software is operating normally while the timer has not timed out, and does not stop the operation of the device to be controlled.

On the other hand, when the software runs out of control, the main control unit 31 becomes uncontrollable and the clear signal is no longer transmitted from the first task 91 to the first monitoring unit 36 . Then, the timer of the first monitoring unit 36 is not reset and the count of the timer is up after a certain period of time has elapsed. When the timer counts up, the first monitoring unit 36 determines that the software runs out of control and the main control unit 31 becomes uncontrollable, and stops the operation of all controlled devices installed in the heat treatment apparatus 1. . That is, the first monitoring unit 36 stops all of the plurality of devices to be controlled when the clear signal is not received from the first task 91 for a certain period of time. At this time, the first monitoring unit 36 may notify the touch panel 33 of the occurrence of an error.

Similarly, while the software is operating normally in the main control unit 31, when the main control unit 31 is executing the second task 92, the second task 92 clears the second monitoring unit 37. A signal is sent. Upon receiving the clear signal from the second task 92, the second monitoring unit 37 resets the timer and restarts counting of the timer. While the software is operating normally, the clear signal is repeatedly transmitted from the second task 92 to the second monitoring unit 37 at regular intervals, and the count of the timer of the second monitoring unit 37 is reset each time. It will be done. The second monitoring unit 37 determines that the software is operating normally and does not stop the operation of the controlled device while the timer has not timed out.

On the other hand, when the software runs out of control, the main control unit 31 becomes uncontrollable and the second task 92 does not transmit the clear signal to the second monitoring unit 37 . Then, the timer of the second monitoring unit 37 is not reset and the count of the timer is up after a certain period of time has passed. When the count of the timer expires, the second monitoring unit 37 determines that the software runs out of control and the main control unit 31 becomes uncontrollable, and stops the operation of the device to be controlled connected to the input/output control unit 32. Let That is, the second monitoring unit 37 stops the operation of the device to be controlled connected to the input/output control unit 32 when the clear signal is not received from the second task 92 for a certain period of time. At this time, the second monitoring unit 37 may notify the touch panel 33 of the occurrence of an error.

Here, when software runs out of control, only some of the tasks may run out of control. For example, in the example of FIG. 9, the first task 91 out of five tasks may operate normally, but only the second task 92 may run out of control. In such a case, assume that the second monitoring section 37 is not provided and only the first monitoring section 36 is provided. Since the first task 91 is operating normally, a clear signal is transmitted from the first task 91 to the first monitoring unit 36, and the count of the timer of the first monitoring unit 36 is reset. Since the timer does not expire, the first monitoring unit 36 determines that the software is operating normally and does not stop the operation of the controlled device.

However, since the second task 92 is actually running out of control, the lamp power supply 49 of the halogen lamp HL, for example, cannot be controlled. As a result, the halogen lamp HL continues to light, and the semiconductor wafer W and the structures in the chamber 6 are overheated. That is, even though the software is running out of control, the first monitoring unit 36 determines that the software is operating normally and does not stop the power supply from the lamp power supply 49, so that the halogen lamp HL continues to light. It becomes.

Therefore, in this embodiment, in addition to the first monitoring section 36, the input/output control section 32 is provided with the second monitoring section 37. FIG. As a result, when only the second task 92 out of the five tasks runs out of control, the clear signal is transmitted from the first task 91 to the first monitoring unit 36, but the second task 92 The clear signal is no longer sent to the unit 37 . The second monitoring unit 37 determines that the software is running out of control when the clear signal is not received from the second task 92 for a certain period of time, and stops the operation of the device to be controlled connected to the input/output control unit 32. stop. As a result, the power supply from the lamp power source 49 is stopped, and the halogen lamp HL is extinguished. That is, even if only the second task 92 out of the five tasks runs out of control, the second monitoring unit 37 detects the run out of control and reliably stops the power supply to the halogen lamp HL. Turn off the light.

In this embodiment, a second monitoring section 37 is provided in addition to the first monitoring section 36 to double monitor software runaway in the main control section 31 . As a result, even if the first monitoring unit 36 cannot detect the runaway even though the software runs out of control and the device to be controlled cannot be controlled, the second monitoring unit 37 detects the runaway. It is possible to stop the operation of the controlled device that is out of control. That is, by double-monitoring software runaway by the first monitoring unit 36 and the second monitoring unit 37, even if a part of the software prevents it and the control target device becomes uncontrollable, It is possible to reliably stop the operation of the device to be controlled.

Although the embodiments of the present invention have been described above, the present invention can be modified in various ways other than those described above without departing from the scope of the invention. For example, in the above embodiment, after the first monitoring unit 36 or the second monitoring unit 37 detects software runaway in the main control unit 31 and stops the operation of the device to be controlled, the main control unit 31 is restarted. You can do it. The restart of the main control unit 31 may be manually performed by the operator of the heat treatment apparatus 1 .

Further, in the above embodiment, the input/output control unit 32 is provided with the second monitoring unit 37, but the present invention is not limited to this, and the second monitoring unit 37 may be provided in another configuration. .

In the above embodiment, when the software runs out of control, the second monitoring unit 37 detects the run out of control and turns off the halogen lamp HL. . For example, the second monitoring section 37 may close the valve 84 to stop the gas supply to the chamber 6 .

Also, the first monitoring unit 36 and the second monitoring unit 37 may be realized by hardware or may be realized by software.

Further, in the above embodiment, the flash heating unit 5 is provided with 30 flash lamps FL, but the present invention is not limited to this, and the number of flash lamps FL can be any number. . Also, the flash lamp FL is not limited to a xenon flash lamp, and may be a krypton flash lamp. Also, the number of halogen lamps HL provided in the halogen heating unit 4 is not limited to 40, and may be an arbitrary number.

In the above embodiment, the semiconductor wafer W is preheated by using the filament type halogen lamp HL as the continuous lighting lamp that continuously emits light for one second or longer. Preheating may be performed by using a discharge type arc lamp (for example, a xenon arc lamp) as a continuous lighting lamp instead of the halogen lamp HL.

Further, substrates to be processed by the heat treatment apparatus 1 are not limited to semiconductor wafers, and may be glass substrates used for flat panel displays such as liquid crystal display devices or substrates for solar cells.

Further, the technology according to the present invention is not limited to the heat treatment apparatus 1 that performs flash lamp annealing, but may be any substrate processing apparatus that controls a plurality of devices to be controlled by a control unit. Examples of such a substrate processing apparatus include a substrate cleaning apparatus for cleaning a semiconductor wafer W and a coater/developer for applying a resist to a semiconductor wafer W and developing the same.

1 Heat Treatment Apparatus 3 Control Unit 4 Halogen Heating Unit 5 Flash Heating Unit 6 Chamber 7 Holding Unit 10 Transfer Mechanism 20 Lower Radiation Thermometer 25 Upper Radiation Thermometer 31 Main Control Unit 32 Input/Output Control Unit 36 First Monitoring Unit 37 Second Monitoring unit 49 Lamp power source 63 Upper chamber window 64 Lower chamber window 65 Heat treatment space 74 Susceptor FL Flash lamp HL Halogen lamp W Semiconductor wafer

Claims (2)

A substrate processing apparatus for performing a predetermined process on a substrate,
a first control unit that controls the entire substrate processing apparatus;
a plurality of controlled devices provided in the substrate processing apparatus and subject to control by the first control unit;
a second control unit that manages information transmission between the first control unit and some of the plurality of controlled devices;
a first monitoring unit provided in the first control unit and monitoring the operation of software executed by the first control unit;
a second monitoring unit provided in the second control unit and monitoring the operation of the software;
with
The first monitoring unit, when the software does not receive a clear signal from a first task out of a plurality of tasks to be executed by the first control unit for a certain period of time, controls the operation of the plurality of devices to be controlled. stop everything,
The substrate processing, wherein the second monitoring unit stops the part of the plurality of devices to be controlled when a clear signal is not received from a second task among the plurality of tasks for a predetermined period of time. Device. A substrate processing method for performing a predetermined processing on a substrate, comprising:
a control step in which a first control unit that controls the entire substrate processing apparatus controls a plurality of devices to be controlled provided in the substrate processing apparatus;
a first monitoring step in which a first monitoring unit provided in the first control unit monitors operation of software executed by the first control unit;
a second monitoring step in which a second monitoring unit provided in a second control unit that manages information transmission between the first control unit and some of the plurality of controlled devices monitors the operation of the software;
with
In the first monitoring step, when the first monitoring unit does not receive a clear signal from a first task out of a plurality of tasks to be executed by the first control unit by the software for a certain period of time, the Stop all of the multiple controlled devices,
In the second monitoring step, when the second monitoring unit does not receive a clear signal from a second task of the plurality of tasks for a predetermined period of time, the part of the plurality of devices to be controlled is stopped. A substrate processing method characterized by:

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