JPS5835529A - Controlling system for fixed light quantity of reduction projecting exposure device - Google Patents

Abstract

PURPOSE:To measure the quantity of exposure accurately, by arranging an illuminance sensor on a shutter. CONSTITUTION:A reticle 6 is illuminated with the light of a lamp 1 which is condensed by a converging lens 2, and its image is projected to a water 7 through a reduction lens 5. An illuminance sensor 8 which inputs an exposure intensity signal to an integration controlling circuit 4 is attached onto a shutter 6. Since the illuminance sensor 8 is arranged on a light path 9 while the shutter 6 is closed, the intensity of the illumination light is measured accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reduction projection exposure apparatus, and is particularly suitable for printing one chip at a time on a wafer in a step-and-repeat manner with a constant exposure dose.

The conventional constant light amount method had the drawback that the illuminance sensor was attached at a location unrelated to the irradiation surface of the reticle, and therefore the illuminance did not necessarily match the illuminance on the reticle surface.

An object of the present invention is to provide a method that allows constant exposure of the entire wafer with the same amount of light when printing an original image of a reticle on a wafer.

An object of the present invention is that when the entire surface of a wafer is printed, the exposure amount must not change for each chip. You must constantly monitor the exposure and change the brightness of the lamp. Therefore,
By attaching an illuminance sensor to the shutter,
Measure when the shutter is closed, and when it is open,
Holds the previous value and prevents it from changing. Furthermore, by attaching it to the shutter, even if the reticle pattern is complex (poor light transmission), it is sufficient to set the brightness of the lamp once as a parameter.

The overall configuration of the present invention will be explained with reference to FIG.

The reduction projection exposure apparatus includes a lamp 1, a converging lens 2, a shutter 3, an integration control circuit 4, a reduction projection lens 5, a reticle 6, and a Ueno S7.

The light irradiated from the lamp l is converged through the converging lens 2, and by opening and closing the shutter 3, the light is emitted from the converging lens 6.
The wafer 7 is exposed to light through the reduction projection lens 5. When one chip exposure is completed, the shutter 3 is closed and the way 7 is moved to expose the next chip. Expose the entire surface using step-and-repeat steps. Therefore, in order to maintain a constant amount of light for each chip, an illuminance sensor is attached to the shutter 3 on the opposite side of the opening as shown in Figure 2, and the illuminance is measured while the shutter is closed, and the amount of change is sent to the lamp power control circuit. Provides feedback to maintain constant light intensity. Figure 3 shows the relationship between time and illuminance, and since the amount of change is inversely proportional to time and illuminance (a in 10), the method of increasing the illuminance using a feedback circuit for the lamp power (line 11) is to make it a constant light amount. It is a graph. By attaching it to the shutter 3 in this manner, the amount of irradiation on the entire surface of the reticle 6 is successively measured.

According to the present invention, (1) Since measurement is possible for each chip, a constant amount of light can be obtained over the entire wafer.

C) As the sensitivity of the wafer improves, the shutter speed increases, and the time the shutter is closed is longer than the time it is open, which is more effective in maintaining a constant light amount.

(3) Even complex reticle patterns can be measured independently.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of the reduction projection exposure apparatus, FIG. 2 is a front view of the shutter, and FIG. 3 is a relationship diagram of the integration control circuit. DESCRIPTION OF SYMBOLS 1... Lamp, 2... Converging lens, 3... Seater, 4... Integration control circuit, 5... Reducing lens,
6... Reticle, 7... Wafer, 8... Illuminance sensor, 9... Shutter opening, 10... Lamp power consumption (watts), 11... Lamp power control.

Claims (1)

[Claims] 1. A constant light amount control method for a reduction projection exposure apparatus, which is characterized in that the shutter is provided with an illuminance sensor in constant light amount exposure consisting of an illuminance sensor, a shutter, a light source, and an integration control circuit.