JP2007294699A - Exposure apparatus and method, and device manufacturing method - Google Patents

Abstract

An exposure apparatus and method capable of maintaining excellent exposure performance and preventing a decrease in throughput in consideration of changes in exposure aberration with time due to solarization.
An exposure apparatus including a projection optical system for projecting a reticle pattern onto an object to be processed, the projection based on a temporal change in transmittance of each lens constituting the projection optical system by solarization. An exposure apparatus comprising: a determining unit that determines an amount of change in exposure aberration of the optical system; and an adjusting unit that adjusts the exposure aberration of the projection optical system based on the amount of change determined by the determining unit. I will provide a.
[Selection] Figure 6

Description

  The present invention generally relates to an exposure apparatus and method, and more particularly to an exposure apparatus and method for exposing an object to be processed such as a wafer for a semiconductor device and a glass plate for a liquid crystal display element.

  2. Description of the Related Art A projection exposure apparatus has been conventionally used when manufacturing a fine semiconductor element such as a semiconductor memory or a logic circuit by using a photolithography technique. The projection exposure apparatus projects a circuit pattern drawn on a reticle (mask) onto a wafer or the like by a projection optical system and transfers the circuit pattern.

  A projection exposure apparatus is required to accurately transfer a pattern on a reticle onto a wafer at a predetermined magnification (reduction ratio). In order to meet such demands, it is important to use a projection optical system in which aberrations are corrected with high accuracy and excellent in imaging performance. In particular, due to rapid miniaturization of semiconductor elements in recent years, a reduction in pattern resolving power due to aberrations of the projection optical system has become a major problem.

  On the other hand, for example, when the light source is broad, the projection optical system is composed of a plurality of glass materials in order to correct chromatic aberration. It is known that a glass material used for a projection optical system generally changes its transmittance (referred to as “solarization”) when exposure light is continuously irradiated (see, for example, Patent Document 1). Note that solarization has characteristics such as being proportional to the exponent of the irradiation illuminance, having a tendency to saturate with respect to the integrated exposure amount, proportional to the thickness of the glass material, and a change amount depending on the glass material.

When solarization occurs (that is, the transmittance of the glass material changes), the amount of energy absorption of the glass material during exposure changes, so that the amount of lens refractive index change and the amount of lens shape change per unit energy change. Changes in the lens refractive index change amount and the lens shape change amount cause a change in exposure aberration. The exposure aberration is an aberration that occurs when a part of the exposure light is absorbed by the projection optical system when transferring the reticle pattern, and causes a focus change, a distortion change, a spherical aberration change, and the like.
Therefore, the projection exposure apparatus generally has a correction mechanism that grasps the exposure aberration amount in advance by simulation or experiment and corrects the exposure aberration amount (see, for example, Patent Document 2).
JP-A-10-116766 JP-A-8-8178

  However, since the conventional projection exposure apparatus does not consider the change in the transmittance of the glass material due to solarization, the exposure aberration due to the change in the transmittance cannot be corrected. In other words, the conventional projection exposure apparatus has not taken systematic measures against changes in exposure aberration over time due to solarization.

  This is because the mechanism of the change in exposure aberration over time (ie, the exposure aberration due to solarization) has not been elucidated. Further, since the output of the exposure light source was relatively low, there was no problem in manufacturing the semiconductor element even if the exposure aberration changed with time. However, in the projection exposure apparatus using i-line as the exposure light source, the output of the exposure light has more than doubled in recent years due to the improvement of the mercury lamp, and the change of the exposure aberration due to solarization becomes a problem. is expected.

  Note that when the exposure aberration changes over time, the exposure performance (for example, imaging performance) of the projection exposure apparatus deteriorates. Therefore, it is necessary to re-examine a large amount of exposure aberration data and review the exposure aberration coefficient, but this leads to a significant decrease in throughput.

  Therefore, the present invention has an exemplary object to provide an exposure apparatus and method capable of maintaining a superior exposure performance and preventing a decrease in throughput in consideration of a change in exposure aberration with time due to solarization. To do.

  In order to achieve the above object, an exposure apparatus according to one aspect of the present invention is an exposure apparatus including a projection optical system that projects a reticle pattern onto an object to be processed, and constitutes the projection optical system based on solarization. A determining unit that determines a change amount of the exposure aberration of the projection optical system based on an amount of change in transmittance of each lens with time, and an exposure aberration of the projection optical system based on the change amount determined by the determination unit And adjusting means for adjusting.

  An exposure apparatus according to still another aspect of the present invention is an exposure apparatus including a projection optical system that projects a reticle pattern onto an object to be processed, the illuminance of exposure light on the image plane of the projection optical system, and integrated exposure. Measuring means for measuring the amount; storage means for storing a table showing a temporal change amount of transmittance of each glass material used in the projection optical system with respect to the integrated exposure amount; the illuminance, the integrated exposure amount, and the Determining means for determining a change amount of the exposure aberration of the projection optical system based on the table; and adjusting means for adjusting the exposure aberration of the projection optical system based on the change amount determined by the determination means. It is characterized by that.

  An exposure method according to still another aspect of the present invention is an exposure method in which a reticle pattern is exposed on a workpiece via a projection optical system, and the transmittance of each lens constituting the projection optical system by solarization is adjusted. Determining the amount of change with time; determining the amount of change in exposure aberration of the projection optical system based on the amount of change with time of the transmittance of each lens; and determining the change in exposure aberration of the projection optical system determined Adjusting the exposure aberration of the projection optical system based on the amount.

  According to still another aspect of the present invention, there is provided a device manufacturing method comprising: exposing a target object using the above-described exposure apparatus; and developing the exposed target object.

  Further objects and other features of the present invention will become apparent from the preferred embodiments described below with reference to the accompanying drawings.

  According to the present invention, it is possible to provide an exposure apparatus and method capable of maintaining excellent exposure performance and preventing a decrease in throughput in consideration of changes in exposure aberration with time due to solarization.

  Hereinafter, an exposure apparatus according to one aspect of the present invention will be described with reference to the accompanying drawings. In addition, in each figure, the same reference number is attached | subjected about the same member and the overlapping description is abbreviate | omitted. Here, FIG. 1 is a schematic sectional view showing the structure of the exposure apparatus 1 of the present invention.

  The exposure apparatus 1 is a projection exposure apparatus that exposes the circuit pattern of the reticle 20 onto the object to be processed 40. In the present embodiment, the exposure apparatus 1 is a step-and-scan projection exposure apparatus, but a step-and-repeat system can also be applied.

  As shown in FIG. 1, the exposure apparatus 1 includes an illumination device 10, a reticle stage 25 on which a reticle 20 is placed, a projection optical system 30, a wafer stage 45 on which a workpiece 40 is placed, and a sensor 50. And a control unit 60.

  The illumination device 10 illuminates a reticle 20 on which a transfer circuit pattern is formed, and includes a light source unit 12 and an illumination optical system 14.

In this embodiment, the light source unit 12 uses a mercury lamp (i-line (wavelength: about 365 nm)). However, the light source unit 12 is not limited to a mercury lamp, and a laser light source (ArF excimer laser, KrF excimer laser, F ₂ laser, or the like) may be used.

  The illumination optical system 14 is an optical system that illuminates the reticle 20. In this embodiment, the illumination optical system 14 includes an elliptical mirror 141, a shutter 142, a condensing optical system 143, a bending mirror 144, an optical integrator 145, a condensing optical system 146, and a half mirror 147. An image optical system 148.

  The elliptical mirror 141 guides the light beam from the light source unit 12 to the condensing optical system 143. The shutter 142 is disposed between the elliptical mirror 141 and the condensing optical system 143, and passes or blocks the light flux from the light source unit 12 by opening and closing. The condensing optical system 143 includes a condenser lens, a zoom lens, and the like, and makes a light beam having a desired shape incident on the optical integrator 145 via the bending mirror 144. The optical integrator 145 is composed of, for example, a fly-eye lens, and uniformizes the light beam that illuminates the reticle 20.

  The condensing optical system 146 condenses the light beam emitted from the secondary light source near the exit surface of the optical integrator 145 and guides it to the imaging optical system 148 via the half mirror 147. The half mirror 147 reflects the light beam from the condensing optical system 146 toward the imaging optical system 148 and transmits a part of the light beam to the sensor 50 described later. The imaging optical system 148 uses the position of the reticle 20 as an image plane and illuminates the reticle 20 with uniform illuminance.

  The reticle 20 is made of, for example, quartz, on which a circuit pattern to be transferred is formed, and is supported and driven by the reticle stage 25. The pattern of the reticle 20 is projected onto the object 40 via the projection optical system 30. The reticle 20 and the workpiece 40 are optically conjugate. Since the exposure apparatus 1 is a step-and-scan type exposure apparatus, the pattern of the reticle 20 is transferred onto the object to be processed 40 by scanning the reticle 20 and the object to be processed 40 at the speed ratio of the reduction magnification ratio. To do. In the case of a step-and-repeat type exposure apparatus, exposure is performed with the reticle 20 and the object to be processed 40 being stationary.

  The reticle stage 25 supports the reticle 20 and is connected to a moving mechanism (not shown). The reticle stage 25 can employ any configuration known in the art. The moving mechanism (not shown) is constituted by, for example, a linear motor, and can move the reticle 20 by moving the reticle stage 25 in the XY directions.

  The projection optical system 30 forms an image of the pattern of the reticle 20 on the object to be processed 40. As the projection optical system 30, a refractive optical system including only a plurality of lens elements, a catadioptric optical system having a plurality of lens elements and at least one reflection mirror, or the like can be used. A detailed description of the projection optical system 30 of this embodiment will be described later.

  In the present embodiment, the object to be processed 40 is a wafer, but widely includes glass plates and other objects to be processed. A photoresist is applied to the object to be processed 40.

  The wafer stage 45 supports the object to be processed 40 via a wafer chuck (not shown). The wafer stage 45 can employ any configuration known in the art.

  The sensor 50 detects the light beam transmitted through the half mirror 147 and transmits the detection result to the control unit 60.

  In the present embodiment, the control unit 60 calculates the illuminance of the exposure light and the integrated exposure amount on the image plane of the projection optical system 30 based on the detection result of the sensor 50, and monitors the integrated exposure amount. However, the sensor 50 may directly detect the illuminance and exposure amount of the exposure light on the image plane of the projection optical system 30, and in this case, the control unit 60 only needs to monitor the integrated exposure amount.

  Further, the control unit 60 has a memory (not shown) and stores solarization coefficients described later as a table. Using the solarization coefficient, the control unit 60 calculates the temporal change in the transmittance of each of the lenses 32a to 32e constituting the projection optical system 30, and based on the calculation result, the exposure aberration of the projection optical system 30 is calculated. The amount of change (change over time) is calculated. A detailed description of the calculation of the amount of change in exposure aberration by the control unit 60 will be given later. The controller 60 corrects (adjusts) the exposure aberration of the projection optical system 30 by driving the lenses 32a to 32e via the drive mechanism 34 based on the calculated change amount of the exposure aberration. In this embodiment, the control unit 60 stores the solarization coefficient, but may store a table indicating the temporal change amount of the transmittance of each glass material used in the projection optical system 30 with respect to the integrated exposure amount. Good.

  Hereinafter, a detailed configuration of the projection optical system 30 of the present embodiment, a change with time in exposure aberration of the projection optical system 30, and correction thereof will be described.

  The projection optical system 30 of the present embodiment is composed of five lenses 32a to 32e for convenience of illustration, but is generally composed of several tens of lenses. The projection optical system 30 is provided with a drive mechanism 34 that can independently drive each of the lenses 32a to 32e. For example, the driving mechanism 34 can move the lenses 32a to 32e in the optical axis direction, decenter the lenses 32a to 32e with respect to the optical axis, or rotate the lenses 32a to 32e around the optical axis. . This makes it possible to adjust the performance of the projection optical system 30 and correct the change in performance.

  The projection optical system 30 is required to have a performance (for example, an imaging performance) for transferring a fine pattern of several tens to several hundreds of nm. In order to achieve such performance, it is essential to grasp and correct the influence of exposure energy on the performance of changes in the lenses 32a to 32e.

  As a cause of the performance change of the projection optical system 30 due to the exposure energy, there is a change in refractive index (generally expressed as dN / dT) caused by a temperature rise of each of the lenses 32a to 32e. Therefore, in order to suppress a change in the performance of the projection optical system 30 due to a change in the refractive index of each lens 32a to 32e, the projection optical system 30 generally has a glass material with a small change in refractive index or a high transmittance (ie, a high transmittance). Glass material is used to reduce the temperature rise of the lens.

  Even in such a projection optical system 30, each of the lenses 32a to 32e absorbs some exposure energy, so that a change in imaging performance (exposure aberration) occurs, and the exposure aberration is corrected (adjusted). Need arises.

  A typical occurrence of exposure aberration in the projection optical system 30 is shown in FIG. In FIG. 2, the abscissa represents the integrated exposure amount, and the ordinate represents the performance change amount of the projection optical system 30 (the focus change in FIG. 2). Referring to FIG. 2, the performance of the projection optical system 30 starts to change when exposure is started, but it does not change any more when a certain exposure load is applied. This is because the exposure energy absorption and emission of the lenses 32 a to 32 e of the projection optical system 30 are the same. Further, when the exposure is stopped, the temperature of each of the lenses 32a to 32e is lowered due to the release of exposure energy, and the projection optical system 30 returns to the initial performance.

  As for the exposure aberration of the projection optical system 30, in general, the amount of change in the performance of the projection optical system 30 is calculated using the opening / closing of the shutter 142, the illuminance of exposure light, the transmittance of the reticle 20, and the like as parameters. Correction is performed by driving the lenses 32a to 32e.

  However, as described above, an exposure apparatus using a high-power mercury lamp as an exposure light source cannot obtain the performance required for device manufacturing even when exposure aberration correction using conventional parameters is used. Specifically, it has been confirmed that a change with time occurs in the exposure aberration of the projection optical system. Therefore, in the prior art, it is necessary to re-examine a huge amount of exposure aberration data in accordance with a change with time of the exposure aberration of the projection optical system, and the throughput is significantly reduced.

  As a result of earnestly examining the cause of the temporal change of the exposure aberration of the projection optical system 30, the present inventor has found that between the solarization of the lenses 32 a to 32 e (glass material) used in the projection optical system 30 and the temporal change of the exposure aberration. I found out there was a correlation. Further, the inventor defines an expression indicating the change with time of the exposure aberration of the projection optical system 30, and proposes a technique for correcting the exposure aberration using the expression.

  FIG. 3 is a graph showing a change in the transmittance of the glass material A used in the projection optical system 30. In FIG. 3, the abscissa indicates the integrated exposure amount, and the ordinate indicates the change in transmittance (in FIG. 3, the amount of deterioration in transmittance). Referring to FIG. 3, the solid line is the result of an experiment on the durability of the transmittance of the glass material A with the illuminance of the exposure light constant, and it can be seen that the transmittance of the glass material A changes as the integrated exposure amount increases. . The dotted line is the result of experimenting the durability of the transmittance of the glass material A by increasing the illuminance of the exposure light as compared with the case where the illuminance of the exposure light is constant, and the saturation value is different from the result shown by the solid line. I understand that.

  The inventor conducted the above-described experiment for all the glass materials used in the projection optical system 30, and solarization (a change amount of the transmittance of the glass material due to irradiation of exposure light) [%] is defined by the following formula 1. Confirmed that it will be.

  Note that So is a solarization coefficient that depends on the physical properties of each lens 32a to 32e (glass material), I is the illuminance of exposure light on the image plane of the projection optical system 30, C is a constant such as 1.5 or 2.0, and D Is the thickness of each lens 32a to 32e (glass material). In addition, k is a time constant depending on the physical properties of the lenses 32a to 32e (glass material), and t is an exposure light irradiation time.

  FIG. 4 is a graph showing the solarization coefficient So of the glass materials A to F used in the projection optical system 30. Referring to FIG. 4, it can be seen that the solarization coefficient So differs depending on the glass material.

  By using Expression 1, it is possible to predict a change in the transmittance of each of the lenses 32a to 32e constituting the projection optical system 30. FIG. 5 shows the result of simulating the change in exposure aberration of the projection optical system 30 over time by regarding the change of each lens 32a to 32e as the change of light absorption by the lens and comparing it with the actual measurement value.

  In FIG. 5, (a) shows the exposure aberration generation amount (simulation value) in a steady state (saturated state) when solarization does not occur. (B) shows the generation amount (simulation value) of the exposure aberration after the irradiation endurance experiment calculated using Equation 1. Further, (c) shows the amount of exposure aberration (measured value) before the irradiation durability experiment, and (d) shows the amount of exposure aberration generation (actual value) after the irradiation durability experiment.

  Referring to FIG. 5, taking into account the solarization of each of the lenses 32a to 32e, the exposure aberration of the projection optical system 30 is estimated using Equation 1 so that the change in exposure aberration with time can be accurately grasped.

  FIG. 6 is a graph showing the result of simulating the exposure aberration that occurs when the exposure apparatus is used under a certain exposure condition for a predetermined period (for example, 3 years) using Equation (1). In FIG. 6, the abscissa represents the exposure time from the cooling state, and the ordinate represents the amount of exposure aberration generated. The solid line indicates the amount of initial exposure aberration, and the dotted line indicates the amount of exposure aberration after a predetermined period.

  Since the conventional exposure apparatus corrects the exposure aberration of the projection optical system according to the curve shown by the solid line even after a predetermined period, a correction residue is generated. A device manufactured by using a projection optical system including such a correction residue may not reach a sufficient performance (that is, becomes a defective product).

  The exposure apparatus 1 of the present embodiment can minimize the correction residue by reflecting the change in the transmittance of each of the lenses 32a to 32e predicted using Equation 1 in the correction of the exposure aberration. Specifically, the exposure apparatus 1 stores the solarization coefficient So of each lens 32a to 32e (glass material) constituting the projection optical system 30 as a table in the control unit 60. Accordingly, it is possible to accurately estimate the change in transmittance (absorption of exposure light) of each of the lenses 32a to 32e from the illuminance of exposure light and the integrated exposure amount monitored by the sensor 50. Further, the temporal change of the exposure aberration of the projection optical system 30 can be calculated from the change in transmittance of the lenses 32a to 32e, and the projection optical system is driven by driving the lenses 32a to 32e based on the calculation result. 30 exposure aberrations can be corrected with high accuracy.

  As shown in FIG. 7, illumination sensor 52 and 54 may be arranged on reticle stage 25 and wafer stage 45, and the change in transmittance of projection optical system 30 may be actually measured. In this case, the transmittance of the projection optical system 30 can be measured periodically, and the exposure aberration can be corrected according to the amount of change in the transmittance of the projection optical system 30. Here, FIG. 7 is a schematic sectional view showing the structure of the exposure apparatus 1 as one aspect of the present invention.

  The illuminance sensor 52 is located on the reticle surface and can measure the illuminance at an arbitrary position in the illumination area on the reticle 20. The illuminance sensor 54 is located on the surface of the object to be processed, and can measure the illuminance at an arbitrary position on the surface of the object to be processed. By measuring the illuminance with the illuminance sensors 52 and 54, a change in the transmittance of the projection optical system 30 can be measured.

  In the present embodiment, the control unit 60 stores a table indicating the degree of influence on the exposure aberration that accompanies the change in the transmittance of each of the lenses 32a to 32e calculated using Equation 1. Thereby, the control unit 60 can calculate the change amount of exposure aberration with time from the change amount of the transmittance of the projection optical system 30 with high accuracy. When the control unit 60 does not store the above-described table, the change in exposure aberration due to the change in the transmittance of each lens 32a to 32e (glass material) constituting the projection optical system 30 cannot be taken into consideration. A change with time cannot be corrected with high accuracy. For example, just because the overall transmittance of the projection optical system 30 is halved, the amount of exposure aberration generated does not necessarily double.

  In this way, the exposure apparatus 1 can take into account changes in exposure aberration over time due to solarization, maintain excellent exposure performance, and prevent a decrease in throughput.

  In the exposure, the light beam emitted from the light source unit 12 illuminates the reticle 20 by the illumination optical system 14. A light beam that passes through the reticle 20 and reflects the reticle pattern is imaged on the object 40 via the projection optical system 30. The projection optical system 30 used by the exposure apparatus 1 can correct exposure aberrations over time due to solarization with high accuracy. Thereby, the exposure apparatus 1 can implement | achieve the outstanding exposure performance, without reducing a throughput. Therefore, the exposure apparatus 1 can provide high-quality devices (semiconductor elements, LCD elements, imaging elements (CCDs, etc.), thin film magnetic heads, etc.) with higher throughput than before.

  The exposure method in the exposure apparatus 1 described above also constitutes one aspect of the present invention. Specifically, in the exposure method of the present invention, first, the amount of change over time of the transmittance of each lens 32a to 32e due to solarization is obtained. Next, the exposure aberration change amount of the projection optical system 30 is determined (calculated) based on the temporal change amount of the transmittance of each of the lenses 32a to 32e. Next, the exposure aberration of the projection optical system 30 is adjusted (corrected) based on the determined change amount of the exposure aberration of the projection optical system 30. Then, the pattern of the reticle 20 is exposed to the object 40 via the projection optical system 30 in which the exposure aberration is corrected.

  Next, with reference to FIGS. 8 and 9, an embodiment of a device manufacturing method using the above-described exposure apparatus 1 will be described. FIG. 8 is a flowchart for explaining how to fabricate devices (ie, semiconductor chips such as IC and LSI, LCDs, CCDs, and the like). Here, the manufacture of a semiconductor chip will be described as an example. In step 1 (circuit design), a device circuit is designed. In step 2 (reticle fabrication), a reticle on which the designed circuit pattern is formed is fabricated. In step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the reticle and wafer. Step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer created in step 4, and includes processes such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation). Including. In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device created in step 5 are performed. Through these steps, the semiconductor device is completed and shipped (step 7).

  FIG. 9 is a detailed flowchart of the wafer process in Step 4. In step 11 (oxidation), the surface of the wafer is oxidized. In step 12 (CVD), an insulating film is formed on the surface of the wafer. In step 13 (electrode formation), an electrode is formed on the wafer by vapor deposition or the like. Step 14 (ion implantation) implants ions into the wafer. In step 15 (resist process), a photosensitive agent is applied to the wafer. Step 16 (exposure) uses the exposure apparatus 1 to expose a reticle circuit pattern onto the wafer. In step 17 (development), the exposed wafer is developed. In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), the resist that has become unnecessary after the etching is removed. By repeatedly performing these steps, multiple circuit patterns are formed on the wafer. According to the device manufacturing method of the present embodiment, it is possible to manufacture a higher quality device than before. Thus, the device manufacturing method using the exposure apparatus 1 and the resulting device also constitute one aspect of the present invention.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist.

It is a schematic sectional drawing which shows the structure of the exposure apparatus as one side surface of this invention. 3 is a graph showing an example of exposure aberration occurring in the projection optical system of the exposure apparatus shown in FIG. It is a graph which shows the change of the transmittance | permeability of the glass material used for the projection optical system of the exposure apparatus shown in FIG. It is a graph which shows the solarization coefficient So of the glass material used for the projection optical system of the exposure apparatus shown in FIG. 2 is a graph showing the amount of exposure aberration generated in the projection optical system of the exposure apparatus shown in FIG. It is a graph which shows the simulation result of the exposure aberration generate | occur | produced when an exposure apparatus is used for a predetermined period on a certain exposure condition. It is a schematic sectional drawing which shows the structure of the exposure apparatus as one side surface of this invention. It is a flowchart for demonstrating manufacture of devices (semiconductor chips, such as IC and LSI, LCD, CCD, etc.). 9 is a detailed flowchart of the wafer process in Step 4 shown in FIG. 8.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exposure apparatus 10 Illuminating device 12 Light source part 14 Illumination optical system 141 Elliptical mirror 142 Shutter 143 Condensing optical system 144 Bending mirror 145 Optical integrator 146 Condensing optical system 147 Half mirror 148 Imaging optical system 20 Reticle 25 Reticle stage 30 Projection optical System 32a thru | or 32e Lens 34 Drive mechanism 40 To-be-processed object 45 Wafer stage 50 Sensor 52 Illuminance sensor 54 Illuminance sensor 60 Control part

Claims (7)

An exposure apparatus comprising a projection optical system for projecting a reticle pattern onto a workpiece,
Determining means for determining a change in exposure aberration of the projection optical system based on a temporal change in transmittance of each lens constituting the projection optical system by solarization;
An exposure apparatus comprising: an adjusting unit that adjusts an exposure aberration of the projection optical system based on the amount of change determined by the determining unit. When the solarization coefficient depending on the physical property of each lens is So, the illuminance of the exposure light on the image plane of the projection optical system is I, C is a constant, the thickness of each glass material is D, and the physical property of each lens is If the constant is k and the exposure light irradiation time is t,
2. The exposure apparatus according to claim 1, wherein the temporal change [%] of the transmittance of each lens is So × I ^C × D × (1−exp (−kt)). A measuring means for measuring the transmittance of the projection optical system;
2. The determining unit determines a change amount of an exposure aberration of the projection optical system based on the transmittance measured by the measuring unit and a temporal change amount of the transmittance of each lens. The exposure apparatus described.   4. The exposure apparatus according to claim 3, wherein the measuring unit is arranged on a surface where the reticle and the object to be processed are located. An exposure apparatus comprising a projection optical system for projecting a reticle pattern onto a workpiece,
Measuring means for measuring the illuminance and integrated exposure amount of exposure light on the image plane of the projection optical system;
Storage means for storing a table indicating a temporal change amount of transmittance of each glass material used in the projection optical system with respect to the integrated exposure amount;
Determining means for determining an exposure aberration change amount of the projection optical system based on the illuminance, the integrated exposure amount and the table;
An exposure apparatus comprising: an adjusting unit that adjusts an exposure aberration of the projection optical system based on the amount of change determined by the determining unit. An exposure method for exposing an object to be processed through a projection optical system to a reticle pattern,
Obtaining a temporal change amount of transmittance of each lens constituting the projection optical system by solarization;
Determining a change amount of exposure aberration of the projection optical system based on a change amount of transmittance of each lens with time;
Adjusting the exposure aberration of the projection optical system based on the determined change amount of the exposure aberration of the projection optical system. Exposing the object to be processed using the exposure apparatus according to claim 1;
And developing the exposed object to be processed.