JPH0423451A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To enable prevention of deterioration of characteristics of a base by a method wherein the terminal of each of grooves made in the shape of a lattice from the surface of a semiconductor wafer to a depth beyond a P-N junction is so provided as to project from the part of intersection with another groove. CONSTITUTION:Every time when one P-N junction is formed, grooves are made in the shape of a lattice from the surface of a wafer to a depth beyond the P-N junction, and the terminal of each of the grooves 2 and 3 is so provided as to project from the point of intersection with another groove. Even with respect to the outermost ones 1A out of the semiconductor bases formed in the shape of the lattice, accordingly, two of the grooves 2 always intersect each other, and when the wafer is cut along these grooves 2 by a dicer, it is prevented that cutting is made from a grooved part through a part not grooved or from the part not grooved through the grooved part in the periphery of each of the outermost semiconductor bases 1A. By this method, a stress applied to the wafer 10 is reduced and it is avoided that deterioration of characteristics of the semiconductor bases 1A is caused by a mechanical damage.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention involves digging grooves in a grid pattern from one surface of a semiconductor wafer having at least one PN junction parallel to the surface to a depth exceeding the PN junction. The present invention relates to a method of manufacturing a semiconductor device in which a semiconductor wafer is cut along grooves and divided into semiconductor substrates.

[Conventional technology]

Figure 2 shows the structure of a semiconductor wafer (hereinafter referred to as a wafer) in one manufacturing process of conventional semiconductor devices such as diodes, transistors, and ICs, and (a) is a plan view (b).
2A is a sectional view taken along line BB in FIG. 1A, and FIG.

To manufacture a semiconductor device, as shown in FIG. 2, a PN junction is formed on a wafer 10 using a technique such as diffusion,
Grooves 2 are dug in a grid pattern on the surface of this wafer IO. This groove 2 is dug to a depth exceeding the PN junction 5 provided in the neem 10, and the PN junction 5 is exposed along this groove 2.
is covered with a passivation film 4. Next, the wafer is cut along the grooves using a dizer to divide the wafer into semiconductor substrates 1.

[Problem to be solved by the invention]

In the method for manufacturing semiconductor devices described above, when dividing a plurality of semiconductor substrates formed in a lattice shape on the second side of a wafer, the wafer is cut with a cutter along grooves around the semiconductor substrates. Around the outermost semiconductor substrate (indicated by IA in FIG. 2) among the plurality of semiconductor substrates formed in a lattice pattern on top of the semiconductor substrate, from the grooved portion (for example, the portion 11 in FIG. 2) Cutting a part without a groove (for example, part 12 in FIG. 2), or cutting a part with a groove from a part without a groove,
Therefore, a large stress is applied to the wafer, and the semiconductor substrate formed on the outermost periphery is damaged, and there is a risk of deterioration of characteristics.

An object of the present invention is to solve the above-mentioned problems and to manufacture a semiconductor device that reduces the stress applied to the wafer when cutting the wafer to divide the semiconductor substrate, thereby preventing deterioration of the characteristics of the semiconductor substrate. The purpose is to provide a method.

[Failure to solve the problem]

In order to solve the above-mentioned problems, in the method for manufacturing a semiconductor device of the present invention, a small number of PNs parallel to the surface (all 1 PN
PN is formed in a lattice pattern from the surface of the semiconductor wafer on which the bond is formed.
In a method of manufacturing a semiconductor device, a trench is dug to a depth exceeding the junction, a PN junction exposed along the trench is covered with a passivation film, and a semiconductor wafer is cut along the trench to obtain a plurality of semiconductor substrates. , the terminal ends of each of the grooves are provided to protrude from the intersections with other grooves.

[For production]

In the method for manufacturing a semiconductor device of the present invention, grooves are dug in a lattice pattern on a wafer so that their terminal ends protrude from the intersections with other grooves. The semiconductor substrate on the outer periphery also has two grooves that are perpendicular to each other without peeling, and when cutting the wafer along these grooves with a dicer, the semiconductor substrate is separated from the grooved part to the non-grooved part. Alternatively, the grooved portion is no longer cut from the non-grooved portion, thereby reducing stress on the wafer and preventing characteristic deterioration of the semiconductor substrate due to mechanical damage.

〔Example〕

FIG. 1 shows the structure of a wafer in one manufacturing process of a semiconductor device according to an embodiment of the present invention, and (a) is a plan view (
b) is a cross-sectional view taken along A-A of (a), (C) is a cross-sectional view of (a)
FIG. A PN junction 5 is formed on the wafer 10 using a technique such as diffusion, and grooves 2 are dug in a grid pattern on the surface of the wafer 10.

At this time, the end of the groove 2 is dug as a groove 3 to a position protruding from the intersection with another groove. These grooves are dug to a depth exceeding the PN junction 5 provided in the semiconductor wafer, and the PN junction 5 exposed along the groove 2 is covered with a passivation film 4. Next, the wafer is cut along the grooves using a dicer to divide the semiconductor substrate l. In this embodiment, grooves 2 formed in a lattice shape and grooves 3 formed by extending this groove are provided, so that
The outermost semiconductor substrate IA formed in a lattice shape also has two grooves that are perpendicular to each other, and when cutting the wafer along these grooves with a dicer, the grooves around the semiconductor substrate are It is no longer necessary to cut a non-grooved section from a section or a grooved section from a non-grooved section, which reduces stress on the wafer and prevents the semiconductor substrate from having its properties deteriorated due to mechanical damage. can avoid.

Note that if this extended groove 3 is dug all the way to the outer edge of the wafer, the mechanical strength of the wafer will decrease, so this groove should not reach the outer edge of the wafer 10, and it should be placed around the periphery of the wafer 10, which is necessary for mechanical strength. It is desirable to provide a section without grooves.

〔Effect of the invention〕

In the method for manufacturing a semiconductor device of the present invention, grooves are formed in a lattice pattern on a wafer so that the terminal ends of the valley grooves protrude from the intersections with other grooves, thereby preventing mechanical damage to the semiconductor substrate when cutting the wafer. Since this structure prevents the deterioration of characteristics due to this type of cause, it has a great effect on improving the yield.

[Brief explanation of drawings]

FIG. 1 shows the structure of a wafer in one manufacturing step in an embodiment of the semiconductor device manufacturing method of the present invention, in which a) is a plan view, (b) is a cross-sectional view taken along line A-A in (a), and (C )teeth(
FIG. 2 shows the structure of a wafer in one manufacturing step in a conventional semiconductor device manufacturing method, FIG. 2 shows a top view, and FIG. FIG. 2B is a cross-sectional view of the semiconductor substrate 1 shown in FIG. 1: Semiconductor substrate, 2: Groove (around semiconductor substrate), 3: Groove (extended), 4: Passivation film, 5: P
N junction, 10: semiconductor wafer. Ku- (b) (C)

Claims (1)

[Claims] 1) trenches are dug in a lattice pattern from the surface of a semiconductor wafer on which at least one PN junction has been formed parallel to the surface to a depth exceeding the PN junction, and the exposed PN junctions are covered with a passivation film along the trenches; A method for manufacturing a semiconductor device in which a semiconductor wafer is cut along the grooves to obtain a plurality of semiconductor substrates, characterized in that the terminal end of each groove is provided to protrude from the intersection with another groove. manufacturing method.