JP2641692B2 - LSI element manufacturing method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing an VLSI device using a projection exposure apparatus capable of easily adjusting optical performance such as magnification and aberration during projection exposure.

[0002]

2. Description of the Related Art In recent years, many reduction projection type exposure apparatuses (hereinafter referred to as "steppers") have been introduced into production sites of VLSI devices.
Although significant results have been achieved, one of the important performances is overlay matching accuracy. An important factor affecting the matching accuracy is a magnification error of the projection optical system. The size of the pattern line width used in the VLSI has been increasingly miniaturized year by year, and accordingly, the need for an improvement in matching accuracy has also increased. Therefore, the necessity of maintaining the projection magnification at a predetermined value has become extremely high. At present, the magnification of the projection optical system is adjusted to be negligible by adjusting the magnification when the apparatus is installed.

[0003]

However, the projection lens of the stepper absorbs a part of the exposure energy and the temperature rises. For this reason, if the projection lens is continuously irradiated with light for exposure for a long time, or if the exposure operation is performed continuously for a long time, the magnification may change to a degree that cannot be ignored. In addition, there is an increasing demand to correct magnification errors when environmental conditions change, such as a slight temperature change around the projection lens and a slight pressure change in a clean room during operation of the apparatus.

The magnification error is 0.05 μm on the image plane.
Even if it is about m, it may be a practical problem, and it is extremely difficult to correct such a minute change in magnification and to always maintain a constant state. In addition, the projection lens not only fluctuates in magnification due to a rise in the temperature of the projection lens due to exposure energy or a change in environmental conditions, but also fluctuates in an image plane position and in various aberrations. However, even if only a certain optical performance, such as magnification, is corrected, deterioration of the overall optical performance may be unavoidable in some cases. Furthermore, since changes in various optical performances are generally not closely related to each other but closely related to each other, it is extremely difficult to positively fine-tune the specific optical performance independently, for example, only the magnification. Was.

SUMMARY OF THE INVENTION It is an object of the present invention to change the magnification of a projection optical system,
It is an object of the present invention to provide a method of manufacturing an VLSI using a projection exposure apparatus capable of easily finely adjusting various optical performances such as a change in an imaging plane position or various aberrations. Another object of the present invention is to provide a projection exposure apparatus capable of independently correcting various optical performances such as aberration.

[0006]

In order to solve such a problem, a first invention defined in claim 1 of the present invention is a method for producing a light beam on a reticle (R) using uniform illumination light.
The present invention is applied to a method of manufacturing an LSI element including a step of illuminating an SI pattern and forming and projecting the LSI pattern on a photosensitive substrate (W) by a projection optical system (1). Optical characteristic adjusting means (pressure controller 12) including means for moving an optical lens element constituting a part of the projection optical system in the optical axis direction.
And air chambers 40, 50, and 60 in the projection optical system 1). The method of manufacturing the LSI element includes an image forming magnification characteristic and an image plane position characteristic of the projection optical system (1) itself, which determines the image forming performance of the LSI pattern projected on the photosensitive substrate (W) by the optical characteristic adjusting means. Of an LSI pattern projected on a photosensitive substrate (W) by adjusting at least two optical characteristics (for example, imaging magnification and various aberration characteristics) selected in advance among three optical characteristics of aberration characteristics. The main point is to adjust the quality and expose.

[0007]

[0008]

[0009]

In the present invention, when performing projection exposure on a photosensitive substrate, even if the air gap in the projection optical system is pressure-controlled for the purpose of correcting magnification fluctuations, various aberrations caused by the pressure control can be kept sufficiently small. Therefore, high matching accuracy can be obtained. In addition, since the aberration fluctuation of the projection optical system can be independently controlled, the pattern can always be projected with a constant aberration characteristic.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiments of the present invention described below, at least two air chambers among a plurality of air chambers formed by a lens surface in a lens system constituting a projection lens are shielded from outside air, and The two air chambers are connected by communicating with each other, and the optical performance of the projection lens is corrected or fine-tuned by controlling the pressure of the connected air chambers.

As described above, if at least two air chambers are communicated and their pressures are simultaneously controlled, for example, a magnification change due to the pressure control of each air chamber occurs simultaneously, and a fluctuation due to each air chamber is added. , The magnification correction amount per unit control amount can be increased, and fine adjustment of the magnification becomes easy. Moreover, in addition to the magnification variation due to each air chamber, attention is paid to the variation of the imaging plane, and at least two pressure controls are performed jointly.
For example, if two air chambers are selected so that the amount of change in the image plane cancels each other and these are shut off from outside air and pressure is controlled, only the magnification is corrected while keeping the image plane constant. Alternatively, it can be actively adjusted. Conversely, if at least two air chambers in which the fluctuations in magnification cancel each other out are communicated and connected to each other to control the pressure, only the imaging surface can be maintained while maintaining the magnification substantially constant. It is possible to correct or actively adjust. Furthermore, if a combination of a plurality of air chambers can offset both fluctuations in magnification and image plane, only specific aberrations such as spherical aberration, coma, curvature of field or distortion can be independently controlled. It becomes possible to correct.

As described above, when at least two air chambers are connected and connected to control the pressure integrally, the correction amount per unit pressure control amount of a specific optical performance is increased by the combination of the air chambers. It is also possible to independently correct and fine-tune only certain optical performance,
In these cases, the pressure control space is substantially one, and only one pressure control device is required. However, as described above, the optical performance of the projection lens often changes in a complicated manner due to various factors such as a rise in temperature due to the exposure energy of the projection lens and a change in environmental conditions, and it is not possible to correct only specific optical performance. Often sufficient. For this,
By setting a plurality of combined air chambers communicating at least two air chambers as described above and providing a plurality of pressure control devices, the degree of freedom of correction is increased and the simultaneous fluctuation of a plurality of optical performances due to various factors is also excellent. It becomes possible to correct. Therefore, a first embodiment of the present invention will be described next.

Two of the existing lens intervals of the projection objective lens are configured as air chambers that are shielded from the outside air, and when the pressure in the air chamber changes by a unit pressure from the initial magnification setting, the magnification change amount, that is, Suppose that the displacement amounts of the predetermined off-axis image points on the image plane are ΔX ₁ and ΔX ₂ , respectively. It is assumed that some of the air chambers other than the air chamber have the same pressure change as the atmospheric pressure, and that a change in magnification is ΔXp with respect to a change ΔP in the unit pressure of the atmospheric pressure. If the other air chambers among the air chambers formed in the projection lens are hermetically sealed and shielded from the atmosphere, there is no change in atmospheric pressure, so that there is no accompanying magnification change.

Therefore, if the two shut-off air chambers are communicated and connected to an integral air chamber and the pressure of the combined air chamber is controlled, the change in magnification due to a unit pressure change of the atmospheric pressure can be obtained. ΔXp hand, when [Delta] P ₁ pressure control amount of the coupling pressure can be corrected magnification change by atmospheric pressure variations [Delta] P by satisfying _{(1) ΔP 1 (ΔX 1} + ΔX 2) + ΔPΔXp = 0. Here, by selecting the one having the same sign of ΔX ₁ and ΔX ₂ , it is possible to obtain a variation larger than the correction variation due to only one of the air chambers. Fluctuations can be corrected. Accordingly, since the pressure fluctuation width of the air chamber for performing the pressure control is relatively small, there is little possibility of air leak and the control is easy.

By the way, it is generally unavoidable that the imaging surface also fluctuates due to the pressure fluctuation of these two air chambers. Therefore, the third air chamber is also communicated and connected, and pressure control is integrally performed. That is, ΔZ ₁ and ΔZ ₂ are the image plane change amounts with respect to the unit pressure change in the two air chambers, ΔX _{3 is the} magnification change amount with respect to the unit pressure change in the third air chamber, and ΔZ _{3 is} the image plane change amount.
_{When 3} is selected, by selecting a third air chamber that satisfies the relationship of ΔZ ₃ = ΔZ ₁ + ΔZ ₂ ,
It is possible to correct only the magnification while keeping the imaging plane constant. It can be expressed by the following equation: (2) It is sufficient to apply a pressure change to the coupling space of the three air chambers by ΔP ₁ so as to satisfy ΔP ₁ (ΔX ₁ + ΔX ₂ + ΔX ₃ ) + ΔPΔXp = 0. At this time, regarding the change of the imaging plane, ΔP ₁ (ΔZ ₁ + ΔZ ₂ + ΔZ ₃ ) = 0 holds, and there is no change of the imaging plane caused by the pressure control.

[0016] On the other hand, as in the case of integrally pressure control two air chambers, image plane variation [Delta] Z ₁ per unit pressure in each air chamber, [Delta] Z ₂ is substantially cancel each other 2
If one air chamber is selected, it is possible to correct or fine-tune only the magnification without changing the image plane. In other words, the magnification correction becomes independent by satisfying (3) ΔP ₁ (ΔX ₁ + ΔX ₂ ) + ΔPΔXp = 0 while maintaining ΔP ₁ (ΔZ ₁ + ΔZ ₂ ) = 0 with respect to the imaging plane variation. It is possible to do.

Therefore, as described above, by communicating at least two air chambers and integrally controlling the pressure,
The correction amount for a specific optical performance can be made larger, and depending on the selection of the air chamber, only a specific optical performance can be corrected independently. However, in each of the above cases, for example, only the magnification of the optical performances can be independently corrected, but it is not possible to simultaneously correct other optical performances, for example, the fluctuation of the image plane, simultaneously with the magnification. In order to simultaneously correct both the magnification and the imaging plane, it is necessary to provide another air chamber for pressure control. Therefore, as described above, the two air chambers are connected and connected to perform pressure control integrally, and further, the fourth air chamber is shut off from the outside air and pressure is separately controlled. When the magnification change amount due to the unit pressure change in the fourth air chamber is ΔX ₄ , the imaging plane change amount is ΔZ _4, and the pressure control amount of the fourth air chamber is ΔP ₂ ,

[0018]

(Equation 4)

By simultaneously changing the pressure of the two coupled air chambers by ΔP ₁ and the pressure of the fourth air chamber by ΔP ₂ integrally so as to simultaneously satisfy the two conditions, the magnification and the magnification are combined. Fluctuations ΔXp, ΔZp of both with the image plane
Can be simultaneously corrected. The fourth air chamber can be connected to the other air chambers in communication therewith to increase the amount of correction in the same manner as the two air chambers described above. For example, by combining air chambers that can cancel out certain aberrations, it is possible to achieve magnification and image plane correction without changing the aberrations.

In order to simultaneously correct other optical performances such as spherical aberration, coma, field curvature or distortion in addition to the magnification and the image plane, the combined air chamber as described above is required. In addition to the air chamber and the fourth air chamber, an air chamber that can be separately pressure-controlled may be provided. That is, in order to simultaneously correct three of the various optical properties, three independent pressure control spaces may be provided. In general, a number of pressure control spaces equal to the number of optical performances to be corrected may be provided independently.

Factors that cause fluctuations in optical performance such as fluctuations in magnification of the projection lens and fluctuations in the image plane are not only atmospheric pressure, but also environmental temperature and humidity outside the lens barrel, exposure energy incident on the projection lens. Temperature rise, and the like. The magnification change amounts caused by the unit amount changes of these elements are ΔXq, ΔXr, ΔXs, and the image plane change amounts are ΔZq, ΔZr, ΔZs, respectively, and the change amounts of the elements are ΔQ, ΔR, ΔS. , The pressure control amount ΔP ₁ of the two combined air chambers and the pressure control amount ΔP ₂ of the fourth air chamber

[0022]

(Equation 5)

By satisfying both conditions, it is possible to simultaneously correct both the magnification and the image plane. Needless to say, when only one of the magnification and the image plane is corrected, the pressure should be controlled so as to satisfy only one of the above two equations. Also in this case, another air chamber may be communicated with the two air chambers connected to each other to integrally control the pressure, and the fourth air chamber may also be communicated with the other air chamber to integrally control the pressure. Pressure can be controlled.

Here, a description will be given of a projection exposure apparatus (stepper) as an LSI manufacturing apparatus to which the present invention is applied. FIG. 1 is a lens arrangement diagram showing an example of a projection objective used for a stepper. A predetermined pattern on a reticle (R) is reduced and projected on a wafer (W) by the objective. In the drawing, light rays representing the conjugate relationship of the on-axis object point between the wafer and the reticle are shown. This objective lens is composed of a total of 14 lenses of L1, L2,..., L14 in order from the reticle (R) side, and the distance between each lens and the reticle (R), the wafer (W) is sequentially a from the reticle side. , B, c,..., O, a total of 15 air spaces are formed. Table 1 shows the specifications of the objective lens. However,
r is the radius of curvature of each lens surface, D is the center thickness and air gap of each lens, N is the refractive index of each lens with respect to the i-line (λ = 365.0 nm), and the leftmost number in the table is the order from the reticle side. Shall be expressed. D0 is a reticle (R)
D31 represents the distance between the last lens surface and the wafer (W).

[Table 1]

Now, in this objective lens, assuming that the air pressure at air intervals a, b,... O is changed by +137.5 mmHg, the relative refractive index of each air interval is 1.00.
005, and the change in magnification and the change in the imaging plane, that is, the conjugate plane with the reticle (R) are as shown in Table 2. However, the magnification change ΔX is the amount of movement of the image point formed at a position 5.66 mm away from the optical axis when the air pressure does not fluctuate on the imaging plane after the air pressure change in each air interval in μm unit. In this case, a positive sign indicates a case where the image is projected larger (enlarged) on an image forming surface, that is, a predetermined wafer surface when there is no atmospheric pressure fluctuation. Further, the change ΔZ of the image plane is shown as a change of the image forming point on the axis, and the case where the distance from the objective lens is increased is shown as a positive sign. Both values are in μm.

[Table 2]

From the above Table 2, it can be seen that the magnification variation ΔX in the fourth space d, the fifth space e, and the sixth space f is a large negative value. Therefore, if the fourth, fifth, and sixth spaces d, e, and f are communicated with each other to be insulated from the outside air, a considerably large correction value can be obtained, and pressure control for magnification correction can be obtained. The amount can be reduced. Next, regarding the image plane variation amount ΔZ, the variation in the fourth, fifth, and sixth spaces is the largest, and according to the integrated pressure control of these spaces,
It can be seen that the image plane can be largely corrected by a relatively small pressure control amount. Further, it can be seen that the tenth space j, the eleventh space k, and the twelfth space l also greatly affect the fluctuation of the imaging plane, and these tenth, eleventh, twelfth spaces j,
It turns out that the image forming surface can be easily corrected by setting k and l to be connected to each other to block the outside air from the outside air.
Also, regarding the fluctuation of the imaging plane, it can be seen that the absolute values of the fluctuation amounts in the first space a and the second space b are almost equal with different signs and can be almost mutually offset. Of the imaging plane of the fourteenth space n and the fifteenth space o
Can be almost offset by the combination with
It can be seen that the magnification variation between the space and the fifteenth space is a relatively small value, but can be substantially offset each other. Therefore, the fourth, fifth, and sixth spaces d, e, and f are pressure-controlled integrally as joint spaces, and the tenth, eleventh, and twelfth spaces j, k, and l are integrally joined spaces. By separately controlling the pressure, both the magnification and the image plane can be corrected simultaneously. At this time, the first space a and the second space b, and the seventh space g and the fourteenth and fifteenth spaces n and o can substantially cancel each other, so that the pressure fluctuates together with the atmospheric pressure. It is desirable that the third space c, the eighth space h, the ninth space i, and the thirteenth space m as the remaining spaces be closed spaces shielded from the atmosphere so as not to cause fluctuations due to them. Based on the above, a second embodiment will be described below.

FIG. 2 shows the pressure control of the air chamber as described above.
FIG. 1 is a schematic configuration diagram of a projection exposure apparatus capable of performing magnification correction and image plane correction by performing the correction in a space at two places. The projection objective lens (1) reduces and projects the pattern on the reticle (R) uniformly illuminated by the illumination device (2) onto the wafer (W) mounted on the stage (3). In the projection objective lens (1), three air chambers (40, 50, 6) corresponding to the fourth space d, the fifth space e, and the sixth space f shown in FIG.
0) is connected by the communicating portion (11a) and is isolated from the atmosphere, and pressure is controlled through the pipe (11) as a first pressure control space. Further, three air chambers (100, 11) corresponding to the tenth space j, the eleventh space k, and the twelfth space l.
0, 120) are connected by a communication part (21a) and are isolated from the atmosphere, and a pipe (21) is used as a second pressure control space.
Pressure controlled through. The air chambers corresponding to the third space c, the eighth space h, the ninth space i, and the thirteenth space m shown in FIG. 1 are air chambers (3
0, 80, 90, 130). A space in which the pressure changes with the atmospheric pressure is omitted from FIG. 2 to avoid complicating the drawing. The first and second pressure control spaces are connected by pipes (11, 21) to pressure controllers (12) and (22) provided outside the projection lens, respectively. Each of the pressure controllers (12, 22) is constantly supplied with air at a constant pressure from a pressurized air supply (4) through filters (13) and (23). It is exhausted according to. On the other hand, pressure sensors (14) and (24) for detecting the internal pressure are provided on the side surfaces of the respective air chambers, and the output signals are sent to a computing unit (5). The measured value of the atmospheric pressure, the temperature outside the projection lens barrel, the humidity, and the temperature inside the barrel are input to the arithmetic unit (5) from the measuring instrument (6) and the temperature sensor (7) in the barrel section. The calculator (5) has a magnification change amount ΔXd, ΔX per unit pressure in the air chamber in each pressure control space.
e, ΔXf; ΔXj, ΔXk, ΔXl and image plane change amounts ΔZd, ΔZe, ΔZf; ΔZj, ΔZk, ΔZl are stored in advance. The arithmetic unit (5) also includes a magnification change ΔXp and an image plane change ΔZp of the projection lens caused by a unit pressure change of the atmospheric pressure, a temperature around the lens barrel,
Magnification fluctuation amount and imaging plane fluctuation amount due to humidity unit amount change,
.DELTA.Xq, .DELTA.Xr; .DELTA.Zq, .DELTA.Zr, and further, magnification change amounts and image plane change amounts .DELTA.Xs, .DELTA.Zs associated with temperature changes of the projection lens due to exposure energy. The arithmetic unit (5) receives the signals from the measuring device (6) and the sensor (7) to change the atmospheric pressure ΔP, the temperature and humidity changes ΔQ, ΔR around the lens barrel, and the projection lens according to the exposure energy. The temperature change amount ΔS is detected, and the pressure change amounts ΔP ₁ and ΔP ₂ necessary for each pressure control space to satisfy both conditions as in the above-described equation (5) are calculated. If the conditions to be satisfied in the present embodiment are described in detail, regarding the magnification change, ΔP ₁ (ΔXd + ΔXe + ΔXf) + ΔP ₂ (ΔXj +
ΔXk + ΔXl) + ΔPΔXp + ΔQΔXq + ΔRΔX
r + ΔSΔXs = 0 Regarding the image plane variation, ΔP ₁ (ΔZd + ΔZe + ΔZf) + ΔP ₂ (ΔZj +
ΔZk + ΔZl) + ΔPΔZp + ΔQΔZq + ΔRΔX
r + ΔSΔXs = 0. Here, .DELTA.Xp and .DELTA.Zp are the sums of the respective amounts of change caused by the air that fluctuates with the atmospheric pressure, and are expressed as: .DELTA.Xp = .DELTA.Xa + .DELTA.Xb + .DELTA.Xg + .DELTA.Xn + .DELTA.Xo.DELTA.Zp = .DELTA.Za + .DELTA.Zb + .DELTA.Zg + .DELTA.Zn + .DELTA.Zo. The signal from the arithmetic unit corresponding to the pressure change amount [Delta] P ₁ and [Delta] P ₂ required for each pressure control space to satisfy these conditions, the pressure controller (12, 22) controls the pressure of the control chamber . In this manner, constant magnification and image plane position are always maintained for each element that affects the optical characteristics of the projection lens, and high-precision matching as a stepper is stably achieved.

In the above embodiment, the fourth, fifth and sixth spaces d, e, f and the first
Although the three lens intervals of each of the 0th, eleventh, and twelfth spaces j, k, and l are employed, the present invention is not limited to this. The number of air chambers for pressure control integrally and the interval to be employed are determined by the objective lens. And the optical performance to be corrected. For example, in the above embodiment, based on the data on the pressure change shown in Table 1, the magnification fluctuation amounts in the third space c and the fourth space d can almost cancel each other. The pressure can also be changed with the atmosphere, and the pressure can be controlled by communicating the two spaces, fifth and sixth spaces e and f. further,
Since the image plane variation amount in the ninth space i can be substantially offset by the combination of the tenth space j and the thirteenth space m, the ninth space i, the tenth space j, and the thirteenth space m also fluctuate with the atmosphere. With this configuration, it is also possible to control the pressure by communicating the eleventh space k and the twelfth space l. At least two air chambers that integrally perform pressure control are advantageous in terms of maintaining pressure uniformity if they are adjacent to each other and also from the structure of the lens barrel, but need not be limited to adjacent air chambers.

In the above embodiment, the signal from the pressure sensor provided in each air chamber is fed back to the pressure controller via the arithmetic unit, and the pressure controller is always operated. It is also possible to configure so that a human reads the value measured by the measuring device, calculates the required pressure change in each air chamber, and manually activates each pressure controller as needed.

As described above, if there are at least two or more spaces in the optical path of the projection optical system that can independently control the atmospheric pressure, changes in both the projection magnification and the image plane position can be controlled.
At this time, if a mechanical adjustment method such as moving the lens element in the projection lens in the direction of the optical axis or changing the distance between the reticle and the projection lens is employed, at least two spaces for controlling the atmospheric pressure are required. do not do. If the stepper has a function of detecting and following a change in the position of the image plane, the control of the atmospheric pressure of the space may be performed only on one space by focusing only on the change in magnification. In a space where the air pressure is not actively controlled, it is desirable to seal the space where the amount of change is large and to keep the air pressure constant.
It is effective from this viewpoint that the space c, the eighth space h, the ninth space i, and the thirteenth space m are sealed. Further, the first space a and the fifteenth space o are spaces between the projection lens and the reticle and between the projection lens and the wafer, respectively, and are generally difficult to shield from the atmosphere. In this regard, as in the above-described embodiment, it is advisable not to seal when the combination with the second space b and the fourteenth space n can substantially cancel each other.

As in the embodiment shown in FIG. 2, a specific lens interval in the projection objective lens is formed in an air chamber which is shielded from the outside air, and fine adjustment of magnification can be performed by controlling the pressure of the air chamber. However, there are various methods of operating such magnification fine adjustment means. First, as in the embodiment shown in FIG. 2, the factors that affect the change in magnification of the stepper and the degree of the influence are checked in advance, and without directly measuring the projection magnification, the variation of each element (for example, the environmental temperature) This is a method in which a change in magnification or a change in atmospheric pressure is measured, the generated change in magnification is predicted, and the magnification fine adjustment means is operated. In this case, as shown in FIG. 2, it is desirable to configure a servo system that measures each influence element in real time and automatically adjusts the magnification immediately, but it is also possible to manually adjust the magnification based on the measured value. .

It should be noted that the relationship between the exposure time and the continuous operation time and the change in the magnification is previously measured by experiments and calculations instead of directly measuring the temperature change due to the energy stored in the projection lens, and the exposure time and the continuous operation are measured. Time information may be fed back to the magnification adjusting means. Further, the stepper can be provided with a projection magnification measuring function, and the measurement result can be fed back to the magnification fine adjustment means. If the magnification can be measured in real time, a servo system that immediately adjusts the magnification can be used. When a long time is required for the measurement, the measured value may be displayed once and the magnification may be manually adjusted based on the value. It is also easy to make a sequence in which the magnification is adjusted based on the measured values and the magnification is rechecked. Since the projection magnification can be known by actually exposing the wafer with a stepper and measuring the wafer, this information can be fed back to the magnification adjusting means.

Heretofore, only the total pressure has been handled without considering the partial pressure of each gas such as N ₂ , O ₂ , CO ₂ , H ₂ O... However, important in adjusting the optical performance of the projection lens is to control the refractive index of air, that is, such that varying the optical characteristics of the optical element of the projection optical path, typically, or using only N ₂ instead of air The present invention naturally includes changing the refractive index of air by controlling the partial pressure of each gas under a constant total pressure. The embodiment of the present invention provides a method that enables fine adjustment of the magnification. It is apparent that the method is useful not only for keeping the magnification constant but also useful for intentionally changing the magnification. .

[0034]

As described above, according to the present invention, it is possible to fine-tune optical aberrations or independently correct various performances in addition to fluctuations in projection magnification and image plane position during projection exposure. Therefore, it is easy to cope with changes in the environmental conditions of the device, high matching accuracy can be maintained, and this greatly contributes to the improvement in the productivity of the VLSI.

[Brief description of the drawings]

FIG. 1 shows a lens configuration of a projection lens of a projection exposure apparatus applied to an embodiment of the present invention.

FIG. 2 shows a schematic configuration of a projection exposure apparatus applied to an embodiment of the present invention.

[Explanation of symbols]

1 Projection objective lens 30, 40, 50, 60, 80, 90, 100, 11
0, 120, 130 Air chamber 12, 22 Pressure controller R Reticle W Wafer

Claims (7)

(57) [Claims] 1. An LSI comprising a step of illuminating an LSI pattern on a reticle with uniformized illumination light and forming and projecting the LSI pattern on a photosensitive substrate by a projection optical system.
In the method for manufacturing an element, optical characteristic adjusting means including means for moving an optical lens element constituting a part of the projection optical system in the optical axis direction is provided, and the optical characteristic adjusting means is provided on the photosensitive substrate. At least two optics selected in advance among three optical characteristics of the projection optical system itself, which affect the imaging performance of the LSI pattern to be projected, such as an imaging magnification characteristic, an image plane position characteristic, and various aberration characteristics. A method for manufacturing an LSI element, comprising changing various characteristics to adjust an image quality of an LSI pattern projected onto the photosensitive substrate and exposing the same. 2. An optical characteristic adjusting unit comprising: a first unit configured to minutely change optical specifications of a specific portion disposed in an imaging optical path from the reticle to the photosensitive substrate; and the optical lens element. And a second means for moving the first and second optical characteristics in the optical axis direction, wherein the at least two optical characteristics selected in advance are adjusted by the combined use of the first means and the second means. 2. The method according to claim 1. 3. The aberration characteristics include spherical aberration, coma,
The method of claim 1, wherein one of the preselected at least two optical properties is the aberration property, including either field curvature or distortion. 4. The optical characteristic adjusting means includes an adjuster for minutely changing optical specifications of a specific portion disposed in an image forming optical path from the reticle to the photosensitive substrate. Of the various optical characteristics other than the image plane position characteristics, the adjustment is performed by the adjuster, and the photosensitive substrate is changed with respect to the image plane position characteristics by changing the image plane of the projection optical system. The method according to claim 1 or 3, wherein the adjustment is performed by a function that follows. 5. The optical characteristic adjusting means includes an adjuster for minutely changing optical specifications of a specific portion arranged in an image forming optical path from the reticle to the photosensitive substrate, and the reticle is adjusted by the adjuster. 2. The method according to claim 1, wherein the at least two preselected optical characteristics are adjusted without changing a positional relationship between the photosensitive substrate and the projection optical system. 6. A specific portion arranged in the image forming optical path includes a first airtight chamber which selects and seals a plurality of specific air intervals among a large number of air intervals constituting the projection optical system, The first airtight chamber is constituted by a second airtight chamber which is different from the first airtight chamber by selecting a plurality of air gaps and communicates with each other, and the adjuster independently changes the refractive index of each gas in the first and second airtight chambers. A method according to claim 4 or claim 5, characterized in that: 7. The controller according to claim 1, wherein the adjuster independently changes the refractive index of each gas in the first and second airtight chambers based on a change in ambient temperature or a change in atmospheric pressure. Item 7. The method according to Item 6.