JPS5837689B2 - hand tai souchi no seizou houhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a semiconductor device, and more particularly to an improvement in the process of coating a semiconductor substrate with a photosensitive resin by a spin coating method.

When manufacturing semiconductor devices, in order to suppress crystal distortion that occurs during the oxidation process, diffusion process, etc. of the semiconductor substrate, gas released from the photosensitive resin coated on the surface of the semiconductor substrate in the first photoetching process is removed from the back side. In order to exhaust the air, a through hole 2 is often formed in the center of the semiconductor substrate 1, as shown in FIGS. 1a and 1b.

Although the size of the through hole is determined according to desire, an effective area of about 0.5 mmφ or more is required to obtain the above effect.

However, when using such a semiconductor substrate with through holes, when applying a photosensitive resin liquid to the substrate in the photolithography process,
It is often the case that the effective area of the through hole is reduced or blocked, reducing its effectiveness.

There is a risk that the photosensitive resin liquid will flow around to the back surface of the substrate through the through holes, causing loss of flatness of the substrate and interfering with etching of fine patterns.

Since a spin coating method is generally used to coat such a through hole with a photosensitive resin liquid on a semiconductor substrate, an example of a spin coating apparatus suitable for this will be described below with reference to FIG. 2.

A rotary chuck consisting of a head 4 having a suction port 3 for suctioning and supporting a semiconductor substrate 1 having a through hole 2 in the center, and a rotary cylindrical portion 6 having an air passage 5 for communicating this suction port with a vacuum source. , an inner ventilation section 7 surrounding the through hole and bonded to the substrate;
is provided in the suction port and is configured to communicate with a ventilation path connected to a vacuum source.

In the rotary chuck configured in this way, the semiconductor substrate with through holes is sucked into the suction port, and at the same time air is blown through the through holes! You will be able to do it.

In this state, when photosensitive resin liquid 8 is dropped into the through hole at the center of the substrate, the center of the droplet is sucked through the through hole and becomes an open hole, as shown in the figure. Although the area is not narrowed or blocked, part of the suctioned portion wraps around the back side of the board, impairing the flatness of the board, and causing minute etched or blocked patterns. There was something that was causing problems.

Therefore, after repeated research on the relationship between the cross-sectional shape of the through hole and the amount of photosensitive resin that wraps around the back surface of the substrate, the following Z results were found.

That is, as shown in FIG. 3, when the angle θ between the inner surface of the through hole and the back surface of the substrate is changed, the amount of wraparound also changes, and when θ is an acute angle such as a, wraparound occurs. No wraparound was observed in cases b and c where θ was an obtuse angle.

The obtuse angle θ is not limited to the one shown in the drawings.

As is clear from the above, in the present invention, by forming the through hole in the semiconductor substrate so that the angle between the inner surface and the back surface of the substrate is an obtuse angle, Since the photosensitive resin is prevented from going around and the pattern etching process is carried out smoothly, highly reliable semiconductor devices can be manufactured.

[Brief explanation of drawings]

1A and 1B are a plan view and a sectional view of a semiconductor substrate having a through hole in the center, FIG. Diagrams a, b
, c are substrate cross-sectional views showing the shapes of through holes drilled in the semiconductor substrate. 1...Semiconductor substrate, 2...Through hole, 3.
...Suction port, 4...Head, 5...
- Ventilation path, 6...Rotating tube section, 7...Internal ventilation path, 8...Photosensitive resin.

Claims (1)

[Claims] 1. It is characterized by including the step of applying a photosensitive resin to the surface of the substrate by a spin coating method by forming an obtuse angle between the inner surface of a through hole formed in the center of the semiconductor substrate and the back surface of the substrate. A method for manufacturing a semiconductor device.