JP2000021725A - Apparatus for manufacturing semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the fluctuations in the expansion ratio of a wafer in a photolithography process for operating pattern formation in a stepper to be used for the photolithography process of a semiconductor device. SOLUTION: The expansion ratio of a reticule fluctuates due to the effects of heat generated on a reticule by an exposure illuminating light, with which a reticule 102 is irradiated so that the effects of heat on the reticule due to the exposure illuminating light can be offset by a reticule part temperature adjusting mechanism 104. Also, the light energy of the exposure illuminating light, with which a wafer 106 is irradiated through a reduced optical system 105 generates heat on the wafer, and the expansion ratio of the wafer changes due to the effects of the heat. Then, a wafer temperature adjusting mechanism 110 is provided at the part of a wafer holder 107 for chucking the wafer 106. Thus, fluctuations in the expansion ratio of the wafer in a photolithography process for operating pattern formation can be suppressed, and highly accuracte pattern formation can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a stepper used in a photolithography process of a semiconductor device.

[0002]

2. Description of the Related Art Conventionally, a stepper used in a photolithography process for forming a pattern of a semiconductor device is a reticle isolated from the surrounding atmosphere as shown in FIG. 2 as disclosed in JP-A-63-104420. By controlling the temperature of the mounting portion, a reduction ratio of a chip exposed on a mask or a wafer is not changed.

[0003]

A stepper used in a conventional photolithography process is disclosed in Japanese Patent Application Laid-Open No. 63-10442.
By providing a temperature control mechanism for controlling the temperature of the reticle mounting portion as disclosed in Japanese Patent Application Publication No. 0-204, the reduction ratio of the chip exposed on the mask or the wafer is kept unchanged. Although the influence of heat from the exposure light source can be reduced, heat is generated on the wafer by light irradiated on the wafer via the reduction optical system 205 shown in FIG. The reduction rate of was fluctuating. At present, in a stepper, the change in the amount of expansion and contraction of the wafer is further increased with the increase in the illuminance of the exposure light source and the increase in the diameter of the wafer.

SUMMARY OF THE INVENTION An object of the present invention is to realize a stepper capable of canceling fluctuations in the expansion and contraction rate of a wafer due to generation of heat on the wafer due to light energy on the wafer during exposure, and performing pattern formation and alignment with high accuracy in a photolithography process. Is to do.

[0005]

In order to achieve the above object, a semiconductor manufacturing apparatus according to the present invention includes a stepper (reduction projection exposure apparatus) used in a photolithography process for forming a pattern in the manufacture of a semiconductor device. A wafer holder (wafer chuck) for attracting a wafer (semiconductor substrate) has a temperature control mechanism. Further, the semiconductor manufacturing apparatus of the present invention is characterized in that the wafer holder and the wafer to be sucked are kept at a constant temperature by using a temperature control mechanism of the wafer holder.

[0006]

According to the semiconductor manufacturing apparatus of the present invention described above, a temperature control mechanism is used for a wafer holder in a stepper used in a photolithography process for forming a pattern in the manufacture of a semiconductor device. Variations in the expansion and contraction rate of the wafer due to the generation of heat on the wafer due to the light energy on the wafer can be canceled, and the pattern on the mask can be accurately exposed on the wafer. As a result, the pattern on the mask is accurately formed at the time of the first exposure, and the accuracy of pattern alignment within the shot is improved at the time of the second and subsequent exposures. At present, in a stepper, light energy on a wafer is increased due to an increase in illuminance of an exposure light source for the purpose of improving processing performance, the amount of heat generated on the wafer is increased, and fluctuations in the expansion and contraction rate of the wafer are increasing. . Further, the exposure range of the stepper has been expanding due to the improvement of the integration degree of the semiconductor device, and the wafer size has been steadily becoming larger in diameter. It is important to cancel the fluctuation of the expansion / contraction ratio of the wafer, which leads to an improvement in the yield and stabilization of the semiconductor device.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the semiconductor manufacturing apparatus of the present invention will be described with reference to the drawings. At present, a stepper is mainly used in a photolithography process for forming a pattern in the manufacture of a semiconductor device. In FIG. 1, reference numeral 101 denotes an ultra-high pressure mercury lamp, an excimer laser, or the like, which is a light source for exposure;
Denotes a reticle mounting unit for vacuum-sucking and fixing the reticle 102.

[0008] Exposure illumination light applied to a reticle 102 is transmitted from an exposure light source 101 via an input lens, a fly-eye lens, and a condenser lens of an exposure illumination system.
The reticle 102 on the reticle mounting portion 03 is uniformly irradiated. At this time, the expansion and contraction rate of the reticle fluctuates due to the effect of heat generated on the reticle due to the exposure illumination light applied to the reticle 102, and the influence of heat on the reticle due to the exposure illumination light by the reticle temperature control mechanism 104 shown in FIG. Counteract. Next, the exposure illumination light applied to the reticle 102 is applied to the wafer 106 vacuum-adsorbed to the wafer holder 107 via the reduction optical system 105. Here, the light energy of the exposure illumination light applied to the wafer 106 via the reduction optical system 105 generates heat on the wafer, and the influence of the heat changes the expansion / contraction ratio of the wafer. Therefore, a wafer temperature control mechanism indicated by 110 is provided at a portion of the wafer holder 107 for sucking the wafer 106. 1
The wafer temperature control mechanism 10 is constituted by a cooling mechanism and a heater, and the cooled fluid is kept at a set temperature by the heater and circulates through the wafer holder 107. The fluid circulated from the above-described temperature control mechanism keeps the wafer holder 107 constant at a set temperature. Further, by using a material having good heat conductivity for the wafer holder 107, the influence of heat on the wafer due to the exposure illumination light applied to the wafer 106 can be canceled, and the fluctuation of the expansion and contraction rate of the wafer can be suppressed.

[0009]

According to the semiconductor manufacturing apparatus of the present invention described above, a temperature control mechanism is used for a wafer holder that sucks a wafer in a stepper used in a photolithography process for forming a pattern in the manufacture of a semiconductor device. Variations in the expansion and contraction rate of the wafer due to the generation of heat on the wafer due to light energy on the wafer during exposure can be canceled, and the pattern on the mask can be accurately exposed on the wafer. As a result, the pattern on the mask is accurately formed at the time of the first exposure, and the accuracy of pattern alignment within the shot is improved at the time of the second and subsequent exposures. At present, in a stepper, light energy on a wafer is increased due to an increase in illuminance of an exposure light source for the purpose of improving processing performance, the amount of heat generated on the wafer is increased, and fluctuations in the expansion and contraction rate of the wafer are increasing. . Further, the exposure range of the stepper has been expanding due to the improvement of the integration degree of the semiconductor device, and the wafer size has been steadily becoming larger in diameter. It is important to cancel the fluctuation of the expansion / contraction ratio of the wafer, which leads to an improvement in the yield and stabilization of the semiconductor device.

[Brief description of the drawings]

FIG. 1 is a plan view showing one embodiment of a semiconductor manufacturing apparatus of the present invention.

FIG. 2 is a plan view showing an embodiment of a conventional semiconductor manufacturing apparatus.

[Explanation of symbols]

 110, 201 Exposure light source 102, 202 Reticle 103, 203 Reticle mounting part 104, 204 Reticle part temperature control mechanism 105, 205 Reduction optical system 106, 206 Wafer 107, 207 Wafer holder 108, 208 XY stage 109, 209 Table 110,210 Wafer temperature control mechanism

Claims (2)

[Claims] A stepper (reduction projection exposure apparatus) used in a photolithography process for forming a pattern in the manufacture of a semiconductor device has a temperature control mechanism on a wafer holder (wafer chuck) for sucking a wafer (semiconductor substrate). Semiconductor manufacturing equipment characterized by the following. 2. The semiconductor manufacturing apparatus according to claim 1, wherein
A semiconductor manufacturing apparatus characterized in that a wafer holder and a wafer to be attracted are kept at a constant temperature by using the wafer holder temperature control mechanism.