JPH0196655A - Glass mask - Google Patents

Abstract

PURPOSE:To improve precision in aligment of a semiconductor substrate and a glass mask by an exposure and developing process by preparing a pattern for orientation flat besides a pattern necessary for forming a semiconductor element. CONSTITUTION:The pattern 2 with which the alignment with the orientation flat part 4, which is formed on the semiconductor substrate 5, can be precisely carried out is set on the glass mask 1 besides the pattern 3 necessary for the semiconductor element. Therefore, the alignment of the direction of the orientation flat part 4 of the semiconductor substrate 5 to be processed and the glass mask 1 can be precisely executed, so that the direction of a Scribing Line formed on the semiconductor substrate 5 to be processed can be made to precisely coincide with that of the orientation flat part. Thus, not only the occurrence of interdigital shape on a section but also the accident such as a break, etc., in the GaAs semiconductor substrate which is solid and fragile can be prevented and moreover the characteristic of the semiconductor element does not receive effects.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an improvement of a glass mask applied to 1st PEP in a PEP process essential for manufacturing semiconductor devices.

(Prior Art) For microwave semiconductor devices, integrated circuit devices, etc., the demand for compound semiconductor devices made of GaAs, which has higher electron mobility and higher saturation drift speed than devices made of silicon, is increasing year by year.

FET and MMICttScri built into GaAs substrate
A blade dicer is used to separate elements by bing.

Since the GaAs substrate, which is hard and brittle, is strained and the device characteristics are affected, a scribing method using a diamond needle that utilizes the gaps in the GaAs single crystal is generally used.

In this case, the cleavage direction of the semiconductor substrate and the Scrib-i
By maintaining the direction of the ng line to an accuracy of at least 1 degree, the cut surface is prevented from forming a sawtooth shape, and if both directions are not maintained within this accuracy, the GaAs substrate may crack. Accidents may occur.

On the other hand, orientation flats (hereinafter referred to as orientation flats) are installed on semiconductor substrates made of silicon, GaAs, etc. to indicate the cleavage direction of the crystal, and recently these orientation flats are sometimes formed in multiple locations. .

By the way, so-called PEP (Photo Engraving Proc.
ess) process is performed several times, and depending on the structure of the element, the process may extend to the middle part or more.

This PEP process requires an exposure and development process, and a mask aligner is used to perform this process, and a method is adopted in which the attached wafer chuck detects the orientation flat part of the semiconductor substrate to be processed and automatically aligns it. ing.

(Problems to be Solved by the Invention) By the way, mechanical means are used to align the orientation flat portion of the semiconductor substrate using the mask aligner, but in some cases, it is inevitable that the direction deviates within a range of several degrees. . If the manufacturing process is continued without sufficient alignment, the cleavage direction of the semiconductor substrate and the Scribin
g The line directions will not match, causing problems.

The present invention provides a novel glass mask that eliminates the above-mentioned drawbacks, and takes particular care to ensure that the direction of the orientation flat part installed on the semiconductor substrate matches the direction of the scribing line formed on this substrate.

[Structure of the invention]

(Means for solving the problem) In order to achieve this object, the glass mask according to the present invention can accurately align with the orientation flat part formed on the semiconductor substrate in addition to the pattern necessary for the semiconductor element. Provides a means to install such patterns. .

(Function) This allows the direction of the orientation flat portion of the semiconductor substrate to be processed to be accurately aligned with the glass mask, so that the direction of the scribing line formed on the semiconductor substrate to be processed and the direction of the orientation flat portion can be accurately matched. As a result, not only a sawtooth shape does not occur on the cut surface, but also accidents such as cracking do not occur even in hard and brittle GaAs semiconductor substrates, and furthermore, the characteristics of the semiconductor element are not affected.

(Example) The present invention will be explained in detail with reference to FIGS. 1 to 5.

FIG. 1 is a top view of a glass mask 1 related to the present invention, and includes patterns 3 for scribing lines.
- In addition, a pattern 2 for the orientation flat part is installed, and the white part in the figure is the part through which light passes. Next, a method of forming a scribing line aligned in the direction of the orientation flat part on a semiconductor substrate using the glass mask 1 will be explained with reference to FIGS. 2 to 5. The wafer is transported, and the orientation flat portion formed on the semiconductor substrate 5 is detected by a wafer chuck installed here, and further aligned with the glass mask.

FIG. 2 is a sectional view of the laminated state of the semiconductor substrate 5 and the glass mask 1 during alignment, and FIG. 3 is a top view thereof.

At this time, it is inspected whether or not the orientation flat portion 4 formed on the semiconductor substrate 5 and the orientation flat pattern 2 of the glass mask 1 are accurately aligned, and if the alignment is deviated, the alignment is performed again. After accurate positioning, exposure and development are performed.

Further, the semiconductor substrate 5 is subjected to an etching process using the photoresist layer 6 as a mask, and then the photoresist layer 6 is removed to obtain the scribing line pattern 3 . (Fig. 5) By the way, this transferred Scribing Line pattern 3...
The interval between ・ (the interval between 2a and 2b) is 1a11.

When the misalignment that occurs in the alignment process of the orientation flat pattern 2 formed on the glass mask 1 is about ±5 μm,
The misalignment with the orientation flat part 2 was 3.4 seconds.0 The semiconductor substrate 5 that has completed the process has a scribing line formed along its cleavage direction, so a scribing process using a diamond needle is performed. However, no sawtooth shape is generated on the cut surface, and therefore the semiconductor device can be completed without affecting its characteristics in any way.

The glass mask 1 used in this example includes an orientation flat pattern and a scribing line to be installed on a semiconductor substrate.
Although the patterns for mask matching are the same mask white pattern, they may be placed on separate masks, and in this case, the pattern for mask matching is formed on the same mask as the pattern for the orientation flat portion.

〔Effect of the invention〕

As described above, the glass mask according to the present invention is provided with an orientation flat pattern in addition to the patterns necessary for forming semiconductor elements, and the alignment accuracy of the semiconductor substrate and glass mask during the exposure and development process is improved by about 1710 degrees compared to that of the conventional one. I was able to improve it in a few seconds.

Therefore, in the scribing process, scribing can be performed accurately along the cleavage direction of the semiconductor substrate.
The cut surface can be formed into a flat shape and can be completed without affecting the characteristics of the elements installed on this semiconductor substrate.

[Brief explanation of the drawing]

FIG. 1 is a top view of a glass mask according to the present invention, FIG. 2 is a cross-sectional view showing a semiconductor substrate aligned with this glass mask, and FIG. 3 is a top view of a semiconductor substrate aligned with this glass mask. FIG. 4 is a cross-sectional view showing the semiconductor substrate subjected to a development process, and FIG.
FIG. 3 is a cross-sectional view showing a state in which the ing line is formed. 1... Glass mask 2... Orientation flat pattern 3-3 Cribbing line pattern 4... Orientation flat 5... Semiconductor substrate 6... Photoresist agent Patent attorney Inoue - Male lineage 1 Figure 2 Figure 35A Figure 4 Figure 5

Claims (1)

[Claims] A glass mask characterized by having a pattern for alignment with an orientation flat formed on a semiconductor substrate.