JPH04352315A - Resist coater - Google Patents

Abstract

PURPOSE:To provide the title resist coater capable of avoiding the readherence of any splashed resist to a wafer in case it is shaked off by a cup regardless of the viscosity of the resist. CONSTITUTION:A rotary cup 5 is fixed to the rotary axle of a motor 4 leaving the lower half of the conventional cup of the title coater as it is. Next, a cup cover 6 moving vertically when a wafer is taken in and out is fixed to the peripheral part of the cup 5. In such a constitution, the splash of the resist when it is shaked off can be eliminated by the rotation of the cup 5 thereby enabling the adherence of a solid matter due to the readherence of the resist and the fluctuation in the film thickness to be avoided.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist coating apparatus for spin coating a resist in a semiconductor device manufacturing process.

0002

2. Description of the Related Art FIG. 3 is a sectional view showing a conventional resist coating apparatus. In the figure, a wafer 1 is held horizontally by suction on a vacuum chuck 2. As shown in FIG. 3 is a nozzle for dropping resist. 4 is a motor for horizontally rotating the wafer 1; 7 is a drain pipe through which the shaken-off resist flows, 8 is an exhaust pipe, and 9 is a fixed cup.

Next, the operation will be explained. A Si wafer 1 for use in a semiconductor device is attracted by a vacuum chuck 2. After an appropriate amount of resist is dropped onto the wafer 1 from the nozzle 3, the vacuum chuck 2 is rotated by the motor 4 at a rotation speed of 3000 rpm to obtain a prescribed film thickness, for example, 1 μm. This rotation spreads the resist uniformly over the entire surface of the wafer 1 to a thickness of 1 μm, and excess resist is shaken off. This shaken-off resist violently hits the surrounding fixed cup 9 due to the centrifugal force generated by the wafer 1 rotating at high speed.

0004

[Problems to be Solved by the Invention] Since the conventional resist coating apparatus is constructed as described above, when shaking off the resist dropped onto the wafer, it rotates at a high speed of, for example, 3000 rpm, so that excess resist is removed. is scattered due to centrifugal force and hits the fixed cup 9 violently. Because the fixed cup 9 is installed near the wafer 1 to be coated due to the structure of the apparatus, the resist that is scattered and violently hits the fixed cup 9 will bounce back onto the wafer 1 and re-adhere. The re-deposited resist causes the film thickness of that portion to fluctuate, which adversely affects the yield of subsequent semiconductor devices. Further, there is a problem in that the redeposited welded resist evaporates and remains as a solid resist, which becomes foreign matter and similarly causes a decrease in yield in the subsequent manufacture of semiconductor devices.

[0005] This invention was made in order to solve the above-mentioned problems, and prevents the shaken off resist from bouncing back, thereby preventing the reduction in yield of semiconductor devices and the influence on the film thickness due to redeposition. The purpose is to obtain a resist coating device.

[0006]

[Means for Solving the Problems] A resist coating apparatus according to the present invention is arranged so that a cup also rotates at the same time as a wafer.

[0007]

In the present invention, since the cup rotates simultaneously with the wafer during resist application, when the excess resist that has been shaken off adheres to the cup, the resist flows along the slope of the cup and is less likely to bounce back onto the wafer.

[0008]

【Example】

Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings. Figure 1
, the motor 4 rotates the wafer 1 and the cup 5 simultaneously in the same direction. Reference numeral 6 denotes a cup cover for maintaining the atmosphere, and the upper part of the cup cover is raised and lowered when the wafer 1 is taken in and taken out. In addition, the same reference numerals as in FIG. 3 indicate the same parts.

Next, the operation will be explained. When an appropriate amount of resist is dropped onto the wafer 1 from the nozzle 3, the resist is first spread uniformly over the surface of the wafer 1 by slow rotation. Thereafter, high-speed rotation is performed to obtain a specified film thickness. For example, 1
Rotate at 3000 rpm to obtain a film thickness of μm. At this time, the excess resist is repelled by centrifugal force, but since the surrounding cups 5 are also rotating, the resist that hits the cup 5 flows in the rotational direction along the slope of the cup 5 and is attached. Therefore, it will not bounce back to the wafer 1 side again.

Embodiment 2 In Embodiment 2 shown in FIG. 2, there is a motor 10 exclusively for the cup,
The cup 5 is rotated in the same direction as the wafer 1 via the belt 11. This allows the rotation speed of the cup 5 to be controlled. For example, when the coating rotation speed is high, the cup 5 can be rotated at a low rotation speed.

[0011]

As described above, according to the present invention, since the cup is configured to rotate, the resist that has been shaken off from the wafer and adhered to it flows outward along the rotational direction of the cup. This has the effect of eliminating the reduction in yield in subsequent semiconductor device manufacturing due to resist solid matter and the reduction in yield in semiconductor device manufacturing caused by film thickness variations.

[Brief explanation of drawings]

FIG. 1 is a front sectional view of Embodiment 1 of the present invention.

FIG. 2 is a front sectional view of a second embodiment of the invention.

FIG. 3 is a front sectional view of a conventional resist coating device.

[Explanation of symbols]

1 Wafer 2 Vacuum chuck 3 Nozzle 4 Motor 5 Cups 6 Cup cover 7 Drain pipe 8 Exhaust pipe 10 Cup rotation motor

Claims (1)

[Claims] 1. A nozzle for dropping resist onto a horizontally supported wafer, a cup disposed surrounding the wafer, and a motor for simultaneously rotating the cup in the same direction as the horizontally rotated wafer. Equipped with resist coating equipment.