JPH04116849A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of chipping in a semiconductor element even when the semiconductor element is mounted with vacuum forceps by forming the rectangular semiconductor element with four round corners. CONSTITUTION:A semiconductor element 23 is formed to have round sections at its four corners. In order to form the element 23 in such way, a wafer l is irradiated with ultraviolet rays through a photomask so as to expose a novolak type positive photoresist 6 applied to sections other than those to be left for semiconductor elements 23 after the photoresist 6 is applied to the surface of the wafer l. The photoresist is developed after exposure. When the pattern of the photomask is formed in accordance with the shape of the semiconductor elements having four round corners, the pattern of the photoresist 6 can be formed. Then the semiconductor elements 23 are obtained from the wafer l in such a way that the wafer l is divided into the elements 23 by selectively etching the wafer l with a reactive gas containing BCl3 and Cl3 by using the photoresist 6 as etching masks and the photoresist is removed by dissolving the photoresist in an organic solvent. Therefore, the occurrence of chipping in the semiconductor elements composed of a compound semiconductor can be prevented even when the elements are handled with vacuum forceps.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is applicable to field effect transistors (hereinafter referred to as FETs) and monolithic microwave integrated circuits (hereinafter referred to as MMICs) using, for example, gallium arsenide GaAs semiconductors. related to semiconductor devices such as

(Conventional technology) Conventionally, FETs use compound semiconductors such as GaAs.

Monolithic microwave integrated circuit (abbreviated as IC in M)
etc. were formed as described below.

That is, as shown in FIG. 2(a),
After performing selective ion implantation, selective formation of various electrode materials and insulators, heat treatment, etc. on a disk-shaped semiconductor substrate known as a semiconductor substrate to form multiple pieces at the same time, they are divided along scribe lines 2 using a diamond blade or the like. Thus, individual semiconductor elements 3 (FIG. 2(b)) are formed.

The semiconductor element 3 thus obtained has a rectangular shape. This semiconductor element is usually mounted on a package or carrier plate using solder or adhesive, and then put into practical use by connecting the electrodes of the semiconductor element and external electrode terminals with gold or aluminum wires. but,
When performing mounting work, semiconductor devices 3 are often handled in a vacuum bin set 4, as shown in FIG.

However, since the above-mentioned compound semiconductor such as GaAs is a relatively brittle material, there is a problem in that the corners of the rectangle are easily chipped when it comes into contact with the vacuum tweezers 4 during the manufacturing process. FIG. 3 illustrates a semiconductor element 13 in which a defective portion 5 has occurred at one corner portion. Semiconductor elements 13 with such defective parts 5 are usually observed to have degraded performance, and even if they are not detected immediately, the deterioration is expected to progress over time, so they are judged to be defective. There is.

Therefore, the above-mentioned conventional semiconductor devices having sharp corners have a disadvantage in that many defective products are generated during mounting.

(Problems to be Solved by the Invention) As described above, in the conventional semiconductor device, the semiconductor element has four sharp corners. the result,
When mounting using vacuum tweezers, it was inevitable that the corners would be damaged, resulting in many failures during mounting.

The present invention has been made to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a semiconductor device including a semiconductor element that prevents the occurrence of damage during mounting using vacuum tweezers.

[Structure of the Invention] (Means for Solving Problem 11) A semiconductor device according to the present invention is a semiconductor device including a semiconductor element obtained by dividing a compound semiconductor wafer into rectangular parts. It is characterized by being formed into a round shape.

(Function) In the semiconductor device of the present invention, the four corners of the semiconductor element are rounded or formed at obtuse angles, thereby making it difficult to cause damage due to contact with vacuum tweezers. .

Therefore, the occurrence of defective products in the mounting process using vacuum tweezers can be prevented.

(Example) Hereinafter, an example of a semiconductor device according to the present invention will be described with reference to the drawings.

The semiconductor element 23 shown in FIG. 1(b) has four corners rounded. In this example, the corners of the semiconductor element are rounded, the size of the radius is constant, and the radius of curvature r is about 176 on the short side (a) of the semiconductor element and about 1/12 on the long side (b). It is.

According to the above configuration, since there are no sharp corners in the portions that come into contact when handling with vacuum tweezers, it is possible to prevent defects caused by defects during mounting.

To realize such a configuration, instead of the conventional dividing method using a diamond blade.

A dividing method using anisotropic selective etching may be employed; what is important at this time is to form the mask used for selective etching into a shape with rounded corners. Specifically, as shown in Figure 1(a),
After applying, for example, a novolak positive photoresist to the surface of the wafer 1, ultraviolet rays are irradiated through a photomask to expose the photoresist other than the portions corresponding to the portions to be left as semiconductor elements, and the photoresist is developed. By making the pattern of the photomask correspond to the shape in which the four corners of the semiconductor element are rounded, the pattern of the photoresist 6 shown in FIG. 1(a) can be formed.

Next, using the photoresist 6 as an etching mask,
The wafer is subjected to selective etching using a reactive gas containing BCQ, and CQ to divide the wafer, and then the photoresist is dissolved and removed using an organic solvent to form the photoresist shown in Figure 1 (b).
) can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, a semiconductor element made of a compound semiconductor can be prevented from being damaged when handled with vacuum tweezers, and a semiconductor element can be prevented from being defective when the semiconductor element is mounted on a package or a carrier plate. equipment can be provided.

[Brief explanation of drawings]

FIG. 1(a) is a plan view for explaining the forming means of an embodiment of the semiconductor element according to the present invention, FIG. 1(b) is a perspective view showing an embodiment of the semiconductor element according to the present invention, Figure 2 (a
) is a plan view for explaining a conventional semiconductor device forming means, FIG. 2(b) is a perspective view showing a conventional semiconductor device, and 3v4 is a perspective view for explaining defects in a conventional semiconductor device FIG. 4 is a perspective view for explaining the state of a semiconductor element after being handled by vacuum tweezers. 1... Wafer, 2... Scribe line, 3.13°23... Semiconductor element. 4...Vacuum tweezers, 5...Defected part.

Claims (1)

[Claims] 1. A semiconductor device comprising a semiconductor element obtained by dividing a compound semiconductor wafer into rectangles, characterized in that the corners of the rectangles in the semiconductor element are rounded.