JP3610232B2 - Manufacturing method of semiconductor device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device such as a light-emitting diode array having a step of forming a semiconductor layer on a wafer and patterning it.
[0002]
[Prior art]
Conventionally, when a semiconductor element such as a light emitting diode array is formed, a plurality of compound semiconductor layers such as GaAs and AlGaAs are formed on a wafer such as Si or GaAs by MOCVD, and the compound semiconductor layer is formed into the shape of the light emitting element. After patterning, it was formed by covering with an insulating film to form a contact hole to be an electrode connection part, then depositing an electrode material and patterning it into an electrode shape, and then dicing into individual light emitting diode arrays .
[0003]
In this case, the semiconductor layer was mesa-etched by depositing and patterning a resist 12 only on the light-emitting dot portions 11 shown in FIGS. 5 (a) and 6 (a). When such mesa etching is performed, the cross-sectional shape of the mesa portion 13 becomes a forward taper in the direction of AA ′ in FIG. 5A, and the electrode (not shown) is taken out. Part. 5A, the cross section is substantially cut and side etching is performed about 2 to 6 μm from the end of the resist 12 as shown in FIG. 6B. The size of the light emitting dot portion 11 in the BB ′ direction was controlled by controlling the amount.
[0004]
[Problems to be solved by the invention]
However, in this conventional method of forming a semiconductor element, only the light emitting dot portion 11 is covered with the resist 12 and the other portions are removed by etching. However, as shown in FIG. There is a problem in that etching residue 15 of the semiconductor film is generated and patterning cannot be performed so that only the light emitting dot portion 11 remains accurately. The reason why the etching residue 15 of the semiconductor film is generated is considered to be that the film thickness distribution and the film quality of the semiconductor film in the peripheral part of the wafer 14 slightly change from the central part, and the etching rate in the depth direction becomes slow.
[0005]
When the mesa etching time is increased in order to reduce the etching residue of the semiconductor film, the side etching amount in the BB ′ direction in FIG. 5A increases, and the size of the light emitting dots 11 (in the BB ′ direction). ) Became smaller and out of standard.
[0006]
In particular, the pitch of the light emitting dots 11 is reduced from 42.3 μm of the conventional 600 dpi to 21.15 μm of 1200 dpi recently, and the influence of overetching is large, so such overetching must be avoided, There is a high possibility that the etching residue 15 is generated.
[0007]
The present invention has been made in view of the above problems of the conventional method, and provides a method for manufacturing a semiconductor element that solves the problem of the conventional method that etching residue of a semiconductor layer formed on a wafer is generated. For the purpose.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, in the method of manufacturing a semiconductor device according to claim 1, a semiconductor layer is formed on a wafer and patterned into a predetermined shape, and then an electrode is formed and cut into individual semiconductor devices. In this manufacturing method, a resist film is deposited on a portion of the semiconductor layer that is to remain, and a narrow resist film is also deposited on a portion of the semiconductor layer that is to be removed. By removing the semiconductor layer by side etching, the semiconductor layer is patterned into a predetermined shape.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a method for producing a semiconductor layer according to the present invention will be described in detail.
A wafer 1 shown in FIG. 1 is manufactured by forming a plurality of semiconductor light emitting elements 2 on one n-type Si substrate. As shown in FIGS. 2 and 3, each semiconductor light emitting element 2 is connected to the n-type Si substrate 4, a plurality of LEDs (semiconductor element body) 5 formed on the front side of the wafer 1, and each LED 5. And a passivation film 9 covering each LED 5 and the front surface 4a of the substrate 4, for example, for exposing a photosensitive drum of a page printer. Used as a light source.
[0010]
Each LED 5 is formed by growing a semiconductor crystal on the surface 4a of the substrate 4 by metal organic vapor phase epitaxy (MOCVD), molecular beam epitaxy (MBE), or the like, and etching the growth layer leaving a portion to become the LED 5. it can. For example, a buffer layer 5a that is a growth layer of gallium arsenide (GaAs), gallium arsenide phosphorus (GaAsP), gallium phosphide (GaP), an n-type semiconductor layer 5b that is a growth layer of aluminum gallium arsenide (AlGaAs), and a p-type semiconductor. The layer 5c and the p ⁺ type semiconductor layer 5d can be used.
[0011]
When this semiconductor layer 5 is patterned into a predetermined shape, as shown in FIGS. 4A and 4B, a resist pattern 10 having a dimension equal to or smaller than the side etching amount is formed in addition to the resist pattern 3 of the light emitting dot portion. When the resist pattern 10 having a dimension equal to or smaller than the side etching amount is formed in this way, the side etching under the resist 10 is performed at the center of the substrate 4 even in the place where the etching residue of the semiconductor film is generated, as shown in FIG. Can be done without changing the part. For this reason, if the resist pattern 10 is dimensioned to be equal to or smaller than the side etching amount, the semiconductor film 5 under the resist pattern 10 is completely removed. In other words, it is considered that when the resist pattern 10 is formed, the periphery of the etching solution around the resist pattern 10 is improved and the etching is accelerated.
[0012]
In this case, the dimension of the resist pattern 10 is not more than the side etching amount. For example, when the side etching amount on one side is 6 μm, the side etching amount on both sides is 12 μm, and the dimension of the resist pattern 10 is 12 μm or less.
[0013]
The pattern 10 for preventing etching residue of the semiconductor film 5 does not have to be formed on the entire surface of the wafer 1, and may be provided at least on the periphery of the wafer 1 where etching residue of the semiconductor film 5 is likely to occur.
[0014]
In this manner, when the patterning is performed by depositing the narrow resist film 10 on the removed portion of the semiconductor film 5 and removing the semiconductor film 5 under the resist film 10 by side etching, the etching time is increased. The remaining etching of the semiconductor film 5 can be prevented in a predetermined etching time. Further, it is only necessary to change the mask of the resist pattern 10, and it is not particularly necessary to increase the number of times of photo or etching.
[0015]
Next, as shown in FIG. 3, a passivation film 9 made of silicon nitride (SiN _x ), silicon oxide (SiO ₂ ), or the like is formed by a plasma CVD method or the like. Each individual electrode 6 is connected to the p ⁺ type semiconductor layer 5d after the p ⁺ type semiconductor layer 5d is exposed by removing a part of the passivation film 9 by etching to form an opening 9a. It is formed by growing and patterning a metal layer by vapor deposition. As the material of the individual electrode 6, gold (Au) or the like that is in ohmic contact with the p ⁺ type semiconductor layer 5d is used. Each common electrode 7 is formed by covering the back surface 4b of the substrate 4 with a metal layer grown by vapor deposition. As the material of the common electrode 7, for example, a three-layer metal material of chrome, antimony, gold (Cr, Sb, Au) that is in ohmic contact with the substrate 4 is used.
[0016]
The wafer 1 is diced between the semiconductor light emitting elements 2 by a diamond blade that rotates at high speed, and is cut into a plurality of semiconductor light emitting elements 2 by the dicing.
[0017]
【The invention's effect】
As described above, according to the method for forming a semiconductor element of the present invention, a resist film is applied to a portion to be left of the semiconductor layer, and a resist film having a narrow width is also applied to a portion to be removed of the semiconductor layer. Since the semiconductor layer is patterned into a predetermined shape by removing the semiconductor layer under the narrow resist film by side etching, the etching time is increased without increasing the etching time. Thus, the remaining etching of the semiconductor film can be prevented. Further, it is only necessary to change the pattern of the resist film, and it is not necessary to increase the number of times of photo or etching.
[Brief description of the drawings]
FIG. 1 is a plan view of a wafer for explaining a method of forming a semiconductor element according to the present invention.
FIG. 2 is a partially enlarged plan view of a wafer for explaining a method for forming a semiconductor element according to the present invention.
FIG. 3 is a cross-sectional view of a semiconductor device for explaining a method for forming a semiconductor device according to the present invention.
4A and 4B are views showing a resist pattern for explaining a method for forming a semiconductor element according to the present invention, wherein FIG. 4A is a plan view, and FIG. 4B is a cross-sectional view taken along the line CC ′ in FIG. (C) is sectional drawing after an etching.
5A and 5B are views showing a resist pattern in a conventional method for forming a semiconductor element, where FIG. 5A is a plan view, FIG. 5B is a cross-sectional view taken along the line AA ′ in FIG. It is a BB 'sectional view taken on the line in FIG.
6A and 6B are enlarged cross-sectional views of a resist pattern portion in a conventional method for forming a semiconductor element, wherein FIG. 6A is an enlarged cross-sectional view before etching, and FIG. 6B is an enlarged cross-sectional view after etching.
7A and 7B are views showing the remaining etching of a semiconductor film in a conventional method for forming a semiconductor element, where FIG. 7A is an overall view, and FIG. 7B is an enlarged view of a portion d in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Wafer, 2 ... Semiconductor light emitting element, 3 ... Resist pattern of light emitting dot part, 4 ... n-type Si substrate, 5 ... LED, 6 ... Individual electrode, 7 ... ··· Common electrode, 8 ···, 9 ··· Passivation film, 10 ······ Resist pattern to prevent etching residue

Claims (1)

In a method for manufacturing a semiconductor element, in which a semiconductor layer is formed on a wafer and patterned into a predetermined shape, and then an electrode is formed and cut into individual semiconductor elements. At the same time, a narrow resist film is also deposited on the portion of the semiconductor layer to be removed, and the semiconductor layer under the narrow resist film is removed by side etching, thereby forming the semiconductor layer into a predetermined shape. A method for manufacturing a semiconductor element, comprising patterning.

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