JPS61196513A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To contrive improvement in productivity of the title semiconductor device without lowering the yield of production and reliability of the device by a method wherein an organic thin film which transmits a laser beam is formed on a semiconductor substrate, and the pattern for recognition is formed on the semiconductor substrate by projecting a laser beam from above the organic thin film. CONSTITUTION:A PEG film 2 is formed on a silicon wafer 1, and when a recog nition pattern is formed on the prescribed part of the silicon wafer 1 by project ing a laser beam 3, the part of the silicon wafer 1 where the laser beam 3 is projected is momentarily fused and scattered by evaporation. As the PEG film 2, wherein the scattering substance of the silicon wafer 1 is contained, is solidified in the deformed state when the projection of the laser beam is stopped, the groove 5 of recognition pattern is formed on the surface of the silicon wafer 1 by removing the PEG film by rinsing. According to this method, no scattering substance is adhered to the wafer surface, and the recognition pattern having the contrast required for an automatic recognition can be formed, thereby enabling to improve the yield of production of the semiconductor device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a semiconductor device, and particularly to a method of forming a recognition pattern on a semiconductor substrate.

[Conventional technology]

In the manufacturing process of semiconductor devices, semiconductor substrates (wafers)
After forming the elements on the wafer, a wafer recognition pattern (wafer rocket number, product name, ROM code,
There is a step of writing (wafer code barcode, etc.).

This wafer recognition pattern is generally written directly on the wafer surface using a laser beam.

[Problem that the invention seeks to solve]

In order to automatically detect this recognition pattern using a recognition device, # of the pattern must be obtained in order to obtain a sufficient contrast H-! It is necessary to form a large

However, when the power of the laser beam is increased in order to enlarge the grooves in the pattern, the area irradiated by the beam boils, and the semiconductor substrate material melts and scatters, adhering to the wafer surface and solidifying, causing defects. This has the drawback of lowering the yield and reliability of semiconductor devices.

Therefore, the recognition pattern must be formed with a low-power laser beam and visually confirmed, which has been a major obstacle to improving productivity.

An object of the present invention is to provide a method for manufacturing semiconductor vicIt that improves productivity by removing the above-mentioned defective metal, preventing scattering of the semiconductor substrate material by a laser beam, and forming a recognition pattern having a contrast layer necessary for automatic recognition. It's about doing.

[Means for solving problems]

The method for manufacturing a semiconductor device of the present invention includes the steps of forming an organic thin film that transmits a laser beam on a semiconductor substrate, and forming a recognition pattern on the semiconductor substrate by irradiating a laser beam onto the organic thin film. It consists of:

According to the present invention, the semiconductor substrate material that boils and scatters due to the laser beam is captured in the organic thin film and removed together with the organic thin film in a subsequent process, so that it does not adhere to the semiconductor substrate and solidify.

〔Example〕

Next, one embodiment of the present invention will be described with reference to the drawings.

FIGS. 1(a) to 1(d) are process cross-sectional views for explaining one embodiment of the present invention.

First, as shown in FIG. 1(a), coating is applied onto a silicon wafer 1 on which a plurality of semiconductor elements are formed, for example, by spin coating on a polyethylene glycol bath solution, to a thickness of 10 to 1
A 00 μm polyethylene glycol thin film (hereinafter referred to as PEG film) is formed.

Although the thickness of the PnG film varies depending on the size, line width, and depth of the pattern formed by the laser beam, it is desirable that the thickness be greater than the line width of the laser beam.

Next, as shown in FIG. 1(b), a predetermined portion of the silicon wafer 1 is irradiated with a laser beam 3t to form a recognition pattern.

By irradiating the laser beam 3, the irradiated portion of the υsilico/wafer 1 is instantly melted and evaporated and scattered. Since the 1'EG film 2 transmits almost 100% of the laser beam 3, it softens due to the evaporation of the silicon wafer 1, but does not reach the point of scattering. Therefore, the scattered objects 4 of the silicon wafer 1 are captured by the softened PEG film and do not scatter to the outside.

When the irradiation of the laser beam 3 is stopped, as shown in FIG.
The membrane 2 solidifies in a deformed state.

Next, by washing the PEσ membrane with water and removing it, as shown in Figure 1 (
As shown in d), a recognition pattern #$5 is formed on the surface of the silicon wafer 1. The scattered particles 4 of the silicon wafer are removed together with the PEG film 2, so that they do not remain on the surface of the silicon wafer 1.

Therefore, even if a recognition pattern is formed by increasing the power of the laser beam, the scattered objects will not remain attached to the surface of the silicon wafer 1.

As described above, according to the embodiments of the present invention, a recognition pattern having a contrast pattern necessary for automatic recognition can be formed without the attachment of flying objects to the wafer surface, thereby improving the efficiency of the semiconductor device manufacturing method. .

Furthermore, since wafer marking and automatic recognition become possible, productivity of semiconductor devices can be improved, especially in high-mix, low-volume production.

In the above embodiments, silicon ware was explained as the semiconductor substrate, but it is not limited to this.
It is also applicable to GaAs and substrates with a silicon single crystal layer formed on the surface of an insulating plate. In addition, PEG is used as an organic thin film.
Although a membrane was used, other methods were used.

Any organic thin film, such as photoresist, which has high laser beam transmittance and is easy to remove after laser beam irradiation can be used.

〔Effect of the invention〕

As explained in detail above, according to the present invention, there is provided a method for manufacturing a semiconductor device that can prevent the scattering of semiconductor substrate material by a laser beam and form a recognition pattern having the contrast necessary for automatic recognition. This has a great effect on improving the productivity of the equipment.

[Brief explanation of drawings]

FIGS. 1(a) to 1(d) are process cross-sectional views for explaining one embodiment of the present invention. 1...Silicon wafer, 2...PEG
jl, 3...Laser beam, 4...Scattered objects, 5...Groove.

Claims (1)

[Claims] A semiconductor device comprising the steps of: forming an organic thin film that transmits a laser beam on a semiconductor substrate; and irradiating a laser beam onto the organic thin film to form a recognition pattern on the semiconductor substrate. Production method.