JPH04142020A - Aligner - Google Patents

Abstract

PURPOSE:To reduce a fluctuation in photoresist pattern sizes by applying ultraviolet rays to a semiconductor substrate always at constant light energy corresponding to a fluctuation in energy for each wavelength. CONSTITUTION:A lamp 1 for generating a plurality of light beams having different wavelengths, a measuring unit 10 for measuring an absolute value of energy for each wavelength of light, a data processing unit 11 for determining a correction amount of the light energy from data stored based on the measured value in advance, and a control unit 15 for controlling the light energy based on the correction amount are provided. Therefore even if energy per wavelength of ultraviolet rays changes, it is possible to automatically correct a combination of filters 4, slit 3 width and brightness of the mercury lamp 1 corresponding to the change to always maintain ultraviolet energy toward a semiconductor substrate 8 constant. Thus an exposure amount to photoresist can be constant and width of a transfer pattern can be uniform to enable highly precise pattern transfer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exposure apparatus that uses ultraviolet rays in the manufacture of semiconductor devices, and particularly relates to an exposure apparatus that uses exposure light that sensitizes a photoresist to a plurality of wavelengths. .

[Conventional technology]

Conventionally, in photolithography technology that uses this type of exposure equipment, when the energy of the light used for exposure changes, the amount of exposure to the photoresist that transfers the pattern changes, causing variations in pattern width dimensions, etc. It is difficult to perform accurate pattern transfer.

To solve this problem, in conventional exposure equipment, a person inserts an optical sensor and an energy measurement sensor into the exposure equipment to measure the light energy, and then uses an adjustment dial on the exposure equipment to maintain the light energy constant. Performing manual adjustment. At this time, with conventional exposure apparatuses, it is not possible to make adjustments for each wavelength of the ultraviolet rays, and the only way to do so is to make adjustments based on the average value of the entire light energy.

[Problem to be solved by the invention]

In the conventional exposure equipment described above, even after adjusting the -degree and light energy key, if there is a change in light energy before the next adjustment, the light energy is corrected for the change. Furthermore, since a sensor is used that has a sensitivity peak near the average value of multiple wavelengths of light, even if the measured light energy is the same, the proportion of light energy at each wavelength is different. There are times when I am.

For this reason, there is a problem in that the above-described exposure amount is excessive or insufficient, and the dimensions of the photoresist pattern of the exposed semiconductor device vary.

An object of the present invention is to provide an exposure apparatus that solves this problem.

[Means to solve the problem]

The exposure apparatus of the present invention includes a lamp that generates a plurality of lights of different wavelengths, a measuring section that measures the absolute value of energy for each wavelength of the light, and a light energy source that calculates the energy of light from pre-stored data based on the measured values. The light source includes a data processing section that determines a correction amount, and a control section that controls light energy based on this correction amount.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an exposure apparatus showing an embodiment of the present invention. As shown in the figure, this exposure apparatus includes a half mirror 5 that divides light generated from a mercury lamp 1 into two parts, which passes through a slit 3 and a filter part 4, and a
a light energy measuring section 10 that measures energy for each wavelength of light transmitted through the light energy measuring section 10; and a data processing section that inputs data from the light energy measuring section 10, compares this data with reference data, and issues a correction command. 11, and a control section 15 including a slit controller 12, a filter controller 13, and a mercury controller 14, which control the aperture of the slit 3, the transmittance of each wavelength of the filter section, and the current supply amount of the mercury lamp 1 according to the correction command. That's what happened.

Also, as in the past, a photomask 6 that transmits the light reflected by the half mirror 5 and a semiconductor device 9 mounted on the carriage 9 converge the light transmitted through the photomask 6.
6 Normally, the light generated from the mercury lamp 1 includes G-line (wavelength: 436 nm), H-line (wavelength: 405 nm), and I-line (wavelength: 365 nm). I'm here. Depending on the sensitivity of the photoresist, the combination of filters in the filter section 4 is changed to select light having an arbitrary wavelength. Furthermore, by adjusting the opening degree of the slit, the amount of light and the shape of the irradiation pattern are adjusted. Furthermore, the light energy of each wavelength can be adjusted by the current supplied to the mercury lamp.

FIG. 2 is a flowchart for explaining the operation of the exposure apparatus shown in FIG. First, in step A, the optical energy measuring section 1
0, the energy insulation value for each wavelength of ultraviolet light that has passed through the slit 3 and the filter section 4 is measured. Then, these data are input to the data processing section 11. Next, the data processing unit 11 compares the inputted energy value with the appropriate energy value stored in advance in step D, and outputs a filter combination signal for correcting the inputted energy value. At the same time, in step H, the data processing unit 11 compares the input energy value relaxation with the appropriate energy sum value stored in advance in step G, and generates a slit width correction command signal for correcting the energy sum value. Output.

Next, in steps E and 1, the filter controller 13 selects a filter combination according to the correction command from the data processing unit 11, the slit controller 12 controls the slit width, and the mercury lamp controller 14 controls the light intensity of the mercury lamp 1. Adjust. Finally, in step F, the optical energy measuring unit measures the absolute value of the energy of each wavelength of the corrected ultraviolet rays, and sends the measured values to the data processing unit 11. Then, the data processing unit 11 compares it with the energy value set as a summary,
Determine whether exposure is possible. Here, if the energy value is within the allowable value, exposure is performed.

If not, the above-described operation is repeated again.

Note that the adjustment of the slit width and the adjustment of the brightness of the mercury lamp may be performed selectively, or both may be performed simultaneously. Furthermore, even if the energy of each wavelength of ultraviolet rays changes, this exposure apparatus automatically corrects the combination of filters, slit width, and brightness of the mercury lamp in response to changes in the energy of each wavelength of ultraviolet rays. It becomes possible to always keep the ultraviolet energy constant.

As a result, the amount of exposure to the photoresist is kept constant, the width of the transferred pattern is made uniform, and highly accurate pattern transfer is achieved.

〔Effect of the invention〕

As explained above, the present invention includes a measuring means for measuring the energy of each wavelength of ultraviolet rays, a filter combination means for determining the combination of filters from pre-stored data, and an energy correction amount based on the correction amount. By providing means to control the slit width and the brightness of the mercury lamp, the semiconductor substrate is always exposed to ultraviolet light with a constant light energy in response to energy fluctuations at each wavelength, and the photoresist pattern dimensions can be adjusted. This has the effect of providing an exposure apparatus that can reduce variations.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an exposure apparatus showing an embodiment of the present invention, and FIG. 2 is a flowchart for explaining the operation of the exposure apparatus of FIG. DESCRIPTION OF SYMBOLS 1... Mercury lamp, 2... Optical path, 3... Slit, 4... Filter part, 5... Half mirror 16...
Photomask, 7... Optical system, 8... Semiconductor substrate,
9... Carriage, 10... Light energy measuring section,
11... Data processing unit, 12... Slit controller, 13... Filter controller, 14... Mercury lamp controller, 15... Control unit.

Claims (1)

[Claims] a lamp that generates a plurality of lights of different wavelengths; a measurement unit that measures the absolute value of energy for each wavelength of the light;
An exposure apparatus comprising: a data processing section that determines a correction amount of light energy from data stored in advance based on the measured value; and a control section that controls the light energy based on the correction amount.