JPH0677112A - Glare protection region control mechanism in aligner - Google Patents

Abstract

PURPOSE:To shield light which is transmitted through a reticle and to transfer a pattern at any region of the reticle to a wafer without causing dust/dirt generated from the movable part of a machine to be adhered to the reticle. CONSTITUTION:A liquid crystal display 1 for transmitting and shielding light projected to a reticle 3 with dark and bright colors is provided, a driving circuit 2 is operated by coordinate value data on a reticle surface input to an input setting part 2a, and any region of the liquid crystal display 1 becomes dark, thus transmitting light only at a desired region for transferring to a wafer. No prior art shielding plate which moves mechanically is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-shielding region mechanism (hereinafter simply referred to as a light-shielding region control mechanism) in an exposure apparatus which sets a region for transferring an integrated circuit pattern on a semiconductor substrate.

[0002]

2. Description of the Related Art FIG. 2 is a diagram showing a main part of an exposure apparatus for explaining a row of a conventional light-shielding area control mechanism. Conventionally, this type of light-shielding region control mechanism has, for example, as shown in FIG. 2, light-shielding plates 6a and 6a for shielding light transmitted through the reticle 3.
b, a drive mechanism (not shown) for moving the light shielding plates 6a, 6b, a detection unit 7 for detecting the positions of the light shielding plates 6a, 6b, and a movement signal for the light shielding plates 6a, 6b provided to the drive mechanism. It has the control part 8 which controls.

In the operation of the light-shielding area control mechanism, first, position information and size-related information data in the area of the reticle 3 of the pattern to be transferred onto the wafer are input to the control section 8. Next, the control unit 8 gives a corresponding output signal to the drive mechanism based on these information data. Next, the drive mechanism moves the light shielding plates 6a and 6b. Then, the signal generated by the detection unit 7 is fed back to the control unit 8, and the light shielding plate 6
The control unit 8 determines whether or not a and 6b have reached the set position, and sends a movement or stop signal to the drive mechanism.

Thus, the reticle 3 is formed. A pattern is arbitrarily selected, and the pattern of the reticle 3 is transferred onto the wafer 5 after being reduced by a reduction lens.

[0005]

The above-described conventional light-shielding area control mechanism is performed by the mechanical operation of the light-shielding plate that determines the exposure area of the reticle, and the reticle is generated by the dust generated by the mechanical operation of the light-shielding plate. However, there is a problem that the pattern is contaminated and causes a defect in the pattern transferred to the wafer.

An object of the present invention is to provide a light blocking area control mechanism for setting a pattern area of a reticle to be transferred onto a wafer without generating dust.

[0007]

A light-shielding area control mechanism in an exposure apparatus according to the present invention includes a liquid crystal plate 1 for receiving light projected from an exposure light source onto a reticle and transmitting only a bright color portion, and arranged vertically and horizontally on the liquid crystal plate. And a drive circuit for operating the liquid crystal element, and an input setting unit for inputting position coordinates of the dark color area of the liquid crystal plate and outputting an operation signal to the drive circuit.

[0008]

The present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a main part of an exposure apparatus for explaining an embodiment of a light shielding area control mechanism of the present invention. As shown in FIG. 1, this light-shielding region control mechanism inputs a liquid crystal plate 1 that selectively shields exposure light, a drive circuit 2 that converts the liquid crystal plate 1 into one of black and white, and a region setting input. Input setting section 2a for outputting a signal according to the setting area to the drive circuit
Is equipped with.

As the liquid crystal plate 1, an ordinary Matrisk liquid crystal element display plate is used, but as the two glass plates, soda lime containing iron having good low transmittance is preferably used. Also,
The drive circuit 2 may be a selection switch circuit that only applies a voltage selectively to the electrodes of the liquid crystal elements arranged vertically and horizontally.
Further, the input setting unit 2a inputs the position coordinates of the area to be shielded from light, and operates the selection switch circuit of the drive circuit 2.

Next, the operation of the light shielding area control mechanism will be described. First, the coordinate value of each corner of the pattern area of the reticle 3 required is input to the input setting unit 2a. As a result, the calculation unit of the input setting unit 2a outputs an ON-OFF signal to the selection switch circuit of the drive circuit 2. Next, the drive circuit 2 outputs a voltage according to the ON-OFF signal, and the liquid crystal element of the liquid crystal plate 1 is turned on or off, so that the region to be shielded becomes black and the exposure light is blocked.

As described above, since there is no mechanically movable part, no dust is generated. There is also an advantage that the area can be changed very easily. Further, the exposure light, which is an ultraviolet ray having a short wavelength, is absorbed by the liquid crystal plate 1, and the portion that transmits the light is a glass substrate having a small amount of iron, so that sufficient contrast can be obtained.

[0012]

As described above, according to the present invention, the matrix liquid crystal display element is used without the mechanically movable portion such as the light shielding plate, and the exposure light is shielded by the dark portion thereof. The effect is that the pattern area of the reticle can be set so as to be transferred to the wafer without generating dust.

[Brief description of drawings]

FIG. 1 is a diagram showing a main part of an exposure apparatus for explaining an embodiment of a light shielding area control mechanism of the present invention.

FIG. 2 is a diagram showing a main part of an exposure apparatus for explaining an example of a conventional light-shielded area control mechanism.

[Explanation of symbols]

 1 liquid crystal plate 2 drive circuit 2a input setting unit 3 reticle 4 reduction lens 5 wafers 6a, 6b light-shielding plate 7 detection unit 8 control unit

Claims (1)

[Claims] 1. A liquid crystal plate 1 for receiving light projected from an exposure light source onto a reticle and transmitting only a bright color portion, a drive circuit for operating liquid crystal elements arranged vertically and horizontally on the liquid crystal plate, and a dark color portion of the liquid crystal plate. A light-shielding region control mechanism in an exposure apparatus, comprising an input setting unit for inputting position coordinates of a region and outputting an operation signal to the drive circuit.