JP2003332208A - Substrate processing equipment - Google Patents

Abstract

(57) [Problem] To provide a substrate processing apparatus capable of improving the temperature uniformity in the heater surface, reducing the load on the heater main body, and preventing the occurrence of cracks. SOLUTION: In a substrate processing apparatus provided with a plurality of heaters for heating a plurality of heating regions, a heating temperature zone of each heater is set to a plurality of temperature zones (T1 or less, T1 to T2, T3 or more).
And the heaters are controlled by the set output values (Z1 to Z4) in each temperature zone, and when the temperature difference between the heaters exceeds an allowable value, the output value of each heater is changed. And heating control.

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a substrate processing apparatus having a heater control function for uniformly and rapidly controlling the temperature of a processing chamber to a high temperature in a substrate processing apparatus. It is. 2. Description of the Related Art Heating control of a heater consists in uniformly raising the temperature of a material to be heated. However, in order to reduce downtime as an apparatus, it is necessary to take a long time to raise the temperature unnecessarily. Can not. For this reason, temperature control is performed using two heaters in order to uniformly raise the temperature and keep the temperature of the susceptor (electrode on which the substrate is mounted) having a large area due to an increase in the size of the substrate. [0003] In order to efficiently control the temperature rise,
The output values of the two heaters are controlled in consideration of the difference in heat absorption and heat transfer of the material to be heated, and control is performed so as to draw a smooth heating curve. FIG. 11 is a graph showing temperature control in a conventional heater. This temperature control is a simple one that sets the set temperature in the temperature controller and waits for the temperature to rise.If there is a difference between the initial temperature and the set temperature, the temperature controller sets the full power until the set temperature is reached. To control heating. For example, when heating from a temperature of 25 degrees to 300 degrees, 300 degrees is set as a set temperature in the temperature controller, and the temperature controller performs heating control from 25 degrees to 300 degrees with full power. FIG. 12 is a block diagram of a conventional substrate processing apparatus for performing temperature control. When the target temperature set value 21 is input and set to the temperature control controller 22 by the user 20, the temperature control controller 22
3 is set in the heater temperature controller 24. The heater temperature controller 24 performs output (%) setting 26 for a heater (susceptor) 25 and detects the temperature as a monitor temperature 27 to perform the heating control. [0005] However, if the temperature is rapidly increased, the load on the heater itself becomes a problem, and it also causes cracks and the like. In particular, as the substrate size of the LCD device increases, the size of the susceptor (electrode on which the substrate is mounted) also increases, and the temperature control of the substrate processing apparatus in which two heaters are embedded in this electrode has the following problems. There is. The in-plane temperature uniformity of the heater is poor. In other words, when two heaters having different capacities are heated to a set temperature to be heated due to the difference in heat capacity and heat transfer of the member to be heated, one of the heaters is easily heated, but the other does not easily rise in a case where much heat is absorbed. . If the heater output is set too high, a load will be applied to the heater, so heating must be carried out over time. This may cause physical load and cracks on the heater body.
That is, if the temperature difference between the inner heater (the inner heater) and the outer heater (the outer heater) is too large, there is a possibility that a crack may be formed in a portion where each heater contacts. In addition, the load caused by applying power increases, and the life of the heater is shortened. An object of the present invention is to provide a substrate processing apparatus capable of solving the above-mentioned problems and improving the temperature uniformity in the heater surface, reducing the load on the heater body, and preventing the occurrence of cracks. The purpose is. SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a substrate processing apparatus having a plurality of heaters for heating a plurality of heating regions, wherein each heater has a plurality of heating temperature zones. When the temperature is divided into temperature zones and the temperature difference between the heaters does not exceed the allowable value, the heaters are controlled with the set output value in each temperature zone and the temperature difference between the heaters exceeds the allowable value. In this case, the heating value is controlled by changing the output value of each heater. Note that, in the embodiment, two heaters, an inner heater and an outer heater, have been described, but the present invention is not limited to a plurality of heaters. Also, a single-wafer apparatus has been described,
It goes without saying that the present invention can be applied to a vertical device. First, an outline of the present invention will be described. In the present invention, as a method of controlling the supply of power to each heater, while performing zone limit control to set a set value in a controller of each heater in a temperature zone,
When a temperature deviation occurs between two heaters (an inner heater and an outer heater), the temperature deviation is fed back to change the set value and control is performed to solve the problem. Hereinafter, these will be described. (1) Zone Limit Control As shown in FIG. 1, a temperature range which the heater can take is divided into a plurality of zones (Z (Z)) divided by an arbitrary temperature (T (n)).
(N)), and the output upper limit value of each temperature control to the inner and outer heaters is determined by the preset output limit parameters (x (n), y (n)) for each zone. As the block configuration diagram, for example, a configuration as shown in FIG. 9 is adopted. The user 30 inputs and sets a target temperature set value and each of the above parameters (T (n), x (n), y (n)) 31 to the temperature controller 32. The temperature controller 32 sets the target temperature set value 34 to the heater temperature controller 33 at the start of the control, and sets the output upper limit value (%) (x (n), y
(N)) 35 is set. The heater temperature controller 33 sets an output (%) 37 for the heater (susceptor) 36 and detects the temperature of the heater 36 as a monitor temperature 38. Further, the monitor temperature 38 is given to the temperature control controller 32, and the temperature control controller determines the current temperature zone Z (n).
Is determined from the monitor temperature and T (n), and the output upper limit values x (n) and y (n) in that temperature band are selected. The above operation will be described later in detail. (2) Temperature Deviation Feedback Control As shown in FIG. 2, a temperature deviation between the inner heater and the outer heater is corrected using the following feedback control. When temperature deviation <-α (when the temperature of the inner heater is high)
Changes the output upper limit value of the inner heater to x (α). When temperature deviation> α (when the temperature of the outer heater is high)
Changes the upper output limit of the outer heater to y (α). As a block diagram, for example, FIG.
The configuration shown in FIG. The user 40 sets each parameter (x (α), y (α), α) 41 in the temperature controller 42. In the temperature controller 42, the outer heater monitor temperature 44 and the inner heater monitor temperature 45
Calculating means 43 for calculating the temperature deviation between heaters from the following. If there is no change in the output value based on the temperature deviation between heaters, or if the output value (x (α)) of the inner heater is changed, or When the output value of the heater is changed based on the determination result, the output upper limit value (%) 49 is set as x.
(Α) and y (α) are output to the heater temperature controller 50.
The heater temperature controller 50 performs an output (%) setting 51 on a heater (susceptor) 53, and detects the temperature of the heater 53 as a monitor temperature 52. The monitor temperature 52 is given to the temperature controller 42 as an outer heater monitor temperature 44 and an inner heater monitor temperature 45. (3) Zone limit control + feedback control FIG. 3 shows a case where each of the zone limit control and the feedback control is used under different conditions. In this control, basically, an output limit set value determined by the zone limit control is used. On the other hand, when the temperature deviation is out of the allowable range, the output upper limit value (x (α), y (α)) by the feedback control described above.
Priority. Here, x (α) and y (α) are set to 0% by default. An upper limit value is set for the value of α in the program, and the value is restricted so that a value exceeding a certain value cannot be set. It should be noted that the parameters x (α), y (α), and α are supplementarily described. Α is an allowable limit temperature deviation (° C.) of mechanical design (hardware) for preventing cracks between heaters due to a temperature difference between heaters. Yes, it is a value incorporated as a fixed value in the program so that the user cannot change it. In the present embodiment, the temperature is set to 20 ° C. x
(Α) and y (α) are the upper limit values of the heater output used when the temperature deviation between heaters exceeds α ° C., and exceed the hardware allowable limit value. However, if the heat release amount of the susceptor is large, setting it to 0% (no output) will cause a rapid temperature drop, and the temperature may fluctuate greatly near the target temperature. In this case, the user can arbitrarily set a value other than 0% in order to alleviate a sudden temperature drop. Hereinafter, a specific configuration of the embodiment will be described. The substrate processing apparatus according to the embodiment will be described by taking an LCD device as an example. FIG. 4 illustrates an example of the parameters used in the embodiment when the temperature zone is four zones. In FIG. 4, Z (n) is determined by the output limit section (T (n)), T (n) is the output limit section boundary temperature (****. *. Degree. C.), and x (n) is the output limit. Division Z
In (n), the inner heater output upper limit (%), y (n) is the outer heater output upper limit (%) in the output limit category Z (n), and x (α) is outside the allowable deviation range (in> out). Inner heater output upper limit value (%), y (α) is the outer heater output upper limit value (%) outside the allowable deviation range (outer> inner), and α is the feedback temperature deviation range (in ° C) between the inner heater and the outer heater.
(Where β> α), x (s) is the upper heater output upper limit value (%) at the heating end temperature (temperature setting temperature), and y (s) is the outer heater at the heating end temperature (temperature adjustment setting temperature). It shows the output upper limit (%). FIG. 5 shows a configuration diagram of the LCD device. Processing chambers indicated by R1, R2, and R3 in FIG. 5 are heater-controlled processing chambers in the embodiment. In FIG. 5,
S1 to S4 are cassette stands, L1 and L2 are load lock chambers with a film thickness measuring device, H is a substrate heating chamber, T2 is a vacuum transfer robot, and T1 is an atmospheric transfer robot. FIG. 6 shows a system configuration diagram of the LCD device. In FIG. 6, a central controller 2 is connected to an operation unit 1, and a board information temporary save memory 3 and local controllers 4 and 5 are connected to the central controller 2. 4A, 5A in the figure
Indicates control contents executed by the local controllers 4 and 5, and the control in the embodiment is executed inside the local controller 5. FIG. 7 is a conceptual diagram of the processing chamber heater control of the LCD device. Thermocouples 12, 16, output thyristors 14, 18, temperature controller 1 for inner and outer heater bodies 11, 15, respectively.
3 and 17 are connected, and the temperature control is controlled by TC
C (temperature control controller) 19 performs the operation collectively. Before performing the temperature control of the target processing chamber, all the parameters shown in FIG. 4 are set and installed in the TCC (temperature control controller) in advance. This parameter is arbitrarily determined by the user, and in order to perform an ideal temperature rise that is speedy and can maintain the in-plane temperature uniformity, the optimal parameters must be verified in advance by experiments. Need to be kept. Hereinafter, the flow of the temperature control will be described with reference to the flowchart of FIG. First, the operation unit or the central controller issues a temperature control command to the TCC via the local controller 5. The temperature control that controls each heater converts an electric signal from a thermocouple attached to the heater into a numerical value, and uses it as a current temperature monitor value. The TCC receives the monitor temperature from the temperature controller at all times, and uses the monitor temperature and the current temperature zone (Z
(N)), and the heater output upper limit (x (n), y (n)) is determined from the temperature zone (zone control: steps S1 to S4). At this time, due to the difference in heating rate of each heater,
When the temperature deviation between the outer heater and the inner heater exceeds the temperature deviation upper limit set by the parameter, the heater output upper limit is changed to x (α) or y (α) (feedback control: step S5, step S6). . The heater output upper limit value finally determined is:
It is transmitted from the TCC to each temperature control, and limits the heater output at each temperature control (step S7). When the temperature difference (temperature difference) between the two heaters becomes large, the heater output of the higher temperature is usually set to 0% (temperature control output upper limit value). Although not shown in FIG. 8, when the temperature deviation is equal to or larger than the alarm output deviation (β), a “temperature deviation alarm” is output on the operation screen to call the user's attention. Can also. In this case, the heater output value may not be changed. In this way, the monitor temperature of the heater is constantly monitored during the temperature increase, the heater output is switched to the heater output upper limit value in the temperature zone at that time, and the process is repeated until the target temperature is reached (step S8). After reaching the target temperature, the heater output upper limit value (x (s), y
(S)), the temperature control command is ended, and an end message is transmitted to the local controller 2. According to the present invention, the following effects can be obtained. First, the heating time from normal temperature to the target temperature is reduced. As a result, the downtime of the apparatus is reduced, and as a result, the operation rate of the apparatus is improved, and the throughput is also improved. Next, the load on the heater itself was reduced, and the occurrence of cracks was eliminated. Further, the temperature difference between the inner and outer heaters was reduced, and in-plane uniformity of the temperature was secured. Also,
An ideal temperature rise curve could be drawn.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing zone limit control in an embodiment of the present invention. FIG. 2 is a diagram illustrating temperature deviation feedback control. FIG. 3 is a diagram showing usage conditions of one or both of zone limit control and feedback control. FIG. 4 is a diagram showing an example of parameters used in the embodiment. FIG. 5 is a diagram illustrating a configuration example of a substrate processing apparatus according to an embodiment. FIG. 6 shows a system configuration diagram of an LCD device in the embodiment. FIG. 7 is a conceptual diagram of processing chamber heater control of the LCD device. FIG. 8 is a flowchart showing temperature control in the embodiment. FIG. 9 is a diagram showing an example of a block configuration diagram of a zone limit control method. FIG. 10 is a diagram illustrating an example of a block configuration diagram of a feedback control method. FIG. 11 is a diagram illustrating temperature control in a conventional substrate processing apparatus. FIG. 12 is a block diagram illustrating an example of temperature control in a conventional substrate processing apparatus. [Description of Signs] 1 Operation Unit, 2 Central Controller, 3 Board Information Temporary Save Memory, 4, 5 Local Controller, 11 Heater (Inner) Body, 12 Heater (Inner) Control Thermocouple, 13 Heater (Inner) Control Temperature controller, 14 heater (inside) output thyristor, 15 heater (outside) body, 16 heater (outside) control thermocouple, 17
Temperature controller for heater (outer) control, 18 Thyristor for heater (outer) output, 19 Sequencer for each temperature control.

Continuation of front page    F term (reference) 3K058 AA02 AA22 AA44 AA64 AA72                       AA86 AA87 BA19 CA12 CA23                       CA69 CB15 CB34 CC09 CE19                       CE26                 5F046 CD01 KA04 KA10

Claims (1)

Claims: 1. A substrate processing apparatus having a plurality of heaters for heating a plurality of heating regions, wherein a heating temperature zone of each heater is divided into a plurality of temperature zones, and a temperature difference between the heaters is determined. If does not exceed the allowable value, the heaters are controlled at the set output value in each temperature zone, and
When the temperature difference between the heaters exceeds an allowable value, the output value of each heater is changed to perform heating control.