JPH11162885A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of device characteristics in a manufacturing process, increase the reliability of the semiconductor device, also increase the manufacturing efficiency, and reduce the manufacturing cost. SOLUTION: This method includes a process, wherein first recesses 6 which pass through a first conductivity-type conductor layer 2 and a second conductivity-type conductor layer 3 are formed from one side of a substrate, on which the first conductivity-type and the second conductivity-type conductor layer 2 and 3 are deposited and a process in which second recesses 7 are so formed as to face opposite to the first recesses 6 from the side of the substrate. The substrate is cut into chips through these processes to make individual semiconductor devices.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device such as a semiconductor memory, a semiconductor laser as a semiconductor light emitting device, and a light emitting diode used for a photocoupler or a remote controller by dicing or the like.

[0002]

2. Description of the Related Art A conventional method for manufacturing a light emitting diode will be described with reference to FIG.

As shown in FIG. 3A, an n-type GaAs epitaxial layer 2 and a p-type GaAs epitaxial layer 3 are sequentially grown on an n-type GaAs substrate (wafer) 1.
Thereafter, a p-type electrode 4 is formed on the p-type GaAs epitaxial layer 3, and an n-type electrode 5 is formed below the n-type GaAs substrate 1.

Next, as shown in FIG. 3B, half dicing is performed from above the wafer with the p-type electrode 4 substantially at the center, thereby forming a dicing groove 6. This dicing groove 6
Has a depth of about 200 μm and separates the p-type GaAs epitaxial layer 3 and the n-type GaAs epitaxial layer 2 from each other.
The pn junction reaches the middle of the type GaAs substrate 1 and separates the pn junction.

[0005] When this dicing is performed, a damaged layer is formed around the dicing groove 6, which can be generally viewed as a saw mark and can be observed as a shift in lattice spacing by the X-ray two-crystal method.

Next, in order to remove a damaged layer at the time of dicing, the dicing groove 6 is etched. After the etching, a wafer inspection is performed.

Next, as shown in FIG. 3 (c), semi-full dicing is performed from above the wafer to a depth of about 10 μm below the bottom of the dicing groove 6 in accordance with the position of the dicing groove 6, and the dicing groove 8 is formed. Form.

At this time, the dicing groove 6 and the dicing groove 8
In some cases, a slight misalignment may occur between the dicing groove 6 and the dicing groove 6 including the pn junction. Then, etching is performed again, and this damaged layer is removed together with the damaged layer in the dicing groove 8.

Through the above steps, a light emitting diode chipped by dicing is manufactured.

[0010] The dicing step is divided into two steps as described above. If the dicing groove is formed deeply by only one dicing step, the wafer may be broken in the next etching step or wafer inspection. Because there is.

[0011]

In the above-described conventional method for manufacturing a semiconductor device, since the wafer inspection is performed after the first dicing, the wafer inspection is usually performed after the second dicing. Do not do. For this reason,
In the second dicing step and the second etching step, even if a defect has occurred, the defect cannot be found. Therefore, if a defect occurs, the device characteristics such as an increase in the leak current of the semiconductor device and a decrease in the optical output in the case of the semiconductor light emitting device occur. Therefore, there arises a problem that the reliability of the semiconductor element is reduced.

Also, two etching steps are required to remove the damaged layer, and it is necessary to protect the front and back surfaces of the wafer each time etching is performed, so that the manufacturing efficiency of semiconductor devices is reduced and the manufacturing cost is reduced. This raises the problem of becoming expensive.

The present invention has been made to solve the problems of the prior art, and can prevent the deterioration of the device characteristics in the manufacturing process, can improve the reliability of the semiconductor device, improve the manufacturing efficiency of the semiconductor device, and reduce the manufacturing cost. It is an object of the present invention to provide a method for manufacturing a semiconductor device capable of reducing the amount.

[0014]

SUMMARY OF THE INVENTION The present invention relates to a method of manufacturing a semiconductor device by manufacturing a semiconductor device by chipping a substrate on which a first conductive type semiconductor layer and a second conductive type semiconductor layer are laminated. Forming a first groove penetrating the first conductivity type semiconductor layer and the second conductivity type semiconductor layer from one side of the substrate; and forming a first groove from the other side of the substrate corresponding to the first groove. And forming a second groove at a position facing the first groove without reaching the first groove, thereby achieving the above object.

[0015] Preferably, the first groove and the second groove are formed in a direction different from a slip plane direction of a crystal constituting the substrate.

Preferably, the first groove and the second groove are formed at 45 degrees with respect to the direction of an orientation flat provided on the substrate.

The operation of the present invention will be described below.

According to the above structure, in the step of forming the first groove in the substrate on which the first conductivity type semiconductor layer and the second conductivity type semiconductor layer are formed, the first groove is formed from one side of the substrate. As a result, the pn junction is separated through the first conductive type semiconductor layer and the second conductive type semiconductor layer. In the next step of forming a second groove, the first groove is placed at a position corresponding to the first groove from the other side of the substrate.
The second groove is formed in a state facing the groove and not reaching the groove.

Therefore, since the second groove is not formed at the pn junction, no damage layer is formed at the pn junction. For this reason, deterioration of device characteristics such as an increase in leakage current of a semiconductor device and a decrease in optical output in the case of a semiconductor light emitting device are eliminated. Further, an etching step for removing the damaged layer after forming the second groove is not required.

Further, the first groove and the second groove are
When the crystal is formed in a direction different from the slip plane orientation of the crystal constituting the substrate, the stress of forming a groove in the weakest slip plane orientation of the crystal is reduced. In particular, when the groove forming direction is inclined by 45 degrees with respect to the direction (110) of the orientation flat 9,
The stress of forming a groove in the direction of the weakest (111) slip plane of the crystal is reduced to 1 / √2. For this reason, (11)
1) A stress is applied to the slip surface, and the occurrence of minute slip dislocations is reduced. As a result, deterioration of device characteristics is reduced.

[0021]

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 shows a method for manufacturing a semiconductor device according to the present invention.

As shown in FIG. 1A, an n-type GaAs epitaxial layer 2 and a p-type GaAs epitaxial layer 3 are sequentially grown on an n-type GaAs substrate (wafer) 1.
Thereafter, a p-type electrode 4 is formed on the p-type GaAs epitaxial layer 3, and an n-type electrode 5 is formed below the n-type GaAs substrate 1.

Next, as shown in FIG. 1B, half dicing is performed from above the wafer with the p-type electrode 4 substantially at the center, to form a dicing groove 6. This dicing groove 6
Has a depth of about 200 μm and separates the p-type GaAs epitaxial layer 3 and the n-type GaAs epitaxial layer 2 from each other.
The pn junction reaches the middle of the type GaAs substrate 1 and separates the pn junction.

Next, in order to remove a damaged layer generated during the dicing, the dicing groove 6 is etched. After the etching, a wafer inspection is performed.

Next, as shown in FIG. 1 (c), the dicing groove 6 is positioned at a position corresponding to the dicing groove 6 to a depth of about 10 μm from below the wafer so that the wafer is not divided.
Is formed so as to face the dicing groove 7.

Through the above steps, a light emitting diode chipped by dicing is manufactured.

As described above, since the dicing groove 7 is not formed at the pn junction, no damage layer is formed at the pn junction. For this reason, deterioration of device characteristics such as an increase in leakage current of a semiconductor device and a decrease in optical output in the case of a semiconductor light emitting device are eliminated. Further, an etching step for removing the damaged layer after the dicing groove 7 is formed becomes unnecessary.

Next, the dicing direction in forming the dicing grooves 6 and 7 will be described.

Normally, dicing is performed in a direction parallel and perpendicular to the direction of the orientation flat 9.

However, the above-mentioned light-emitting diode has (10)
It has a laminated structure of a GaAs layer using a GaAs substrate having a plane orientation of (0), and the weakest part of the crystal is a (111) slip plane. Therefore, when a stress is applied to the (111) slip surface during dicing, minute slip dislocations occur.
Due to the defect caused by the slip dislocation, deterioration of device characteristics such as an increase in leak current of the light emitting diode and a decrease in optical output occur.

Therefore, in the present invention, the dicing direction is inclined by 45 degrees with respect to the direction (110) of the orientation flat 9, as shown in FIG. This allows the weakest (11
1) The dicing stress in the sliding surface direction is reduced to 1 / √2. For this reason, stress is applied to the (111) slip surface during dicing, and the occurrence of minute slip dislocations is reduced. As a result, deterioration of device characteristics is reduced.

At the time of the second dicing, a damage layer is formed in a portion other than the pn junction and a defect is generated. However, since the dicing groove 7 is not formed at the pn junction, the pn junction is formed.
No damage layer is formed at the joint. Therefore, the element characteristics of the light emitting diode do not deteriorate.

The dicing method includes a diamond blade scribe method, a diamond point scribe method and a laser scribe method.

[0035]

As described above, according to the method of manufacturing a semiconductor device of the present invention, when the second groove is formed, the groove is not formed at the pn junction, so that a damage layer may be formed at the pn junction. Disappears. Therefore, it is possible to prevent deterioration of device characteristics such as an increase in leakage current of the semiconductor device and a decrease in optical output in the case of a semiconductor light emitting device.

Further, an etching step for removing the damaged layer after the second groove is formed becomes unnecessary, and the number of steps can be reduced, so that the manufacturing efficiency can be improved and the manufacturing cost can be reduced.

Further, since the second groove formation does not affect the device characteristics of the semiconductor device and the subsequent etching step is eliminated, the deterioration of the device characteristics in the manufacturing process can be prevented. Therefore, the result of the wafer inspection after the first groove formation can be used as it is, and the reliability of the semiconductor element is improved.

In particular, according to the method of manufacturing a semiconductor device of the present invention, since the grooves are formed in a direction different from the slip plane direction of the crystal constituting the substrate, the grooves are formed in the direction of the weakest slip plane of the crystal. Since the stress can be reduced, it is effective in preventing the deterioration of the device characteristics.

In addition, according to the method of manufacturing a semiconductor device according to the third aspect, since the groove is formed in a direction at 45 degrees to the direction of the orientation flat provided on the substrate, the groove is formed in the direction of the slip plane of the crystal. Since the stress can be further reduced, it is particularly effective in preventing deterioration of the device characteristics.

[Brief description of the drawings]

FIG. 1 is a diagram showing a method for manufacturing a semiconductor device of the present invention.

FIG. 2 is a diagram showing a dicing direction in a method for manufacturing a semiconductor device of the present invention.

FIG. 3 is a view showing a conventional method of manufacturing a semiconductor device.

[Explanation of symbols]

 Reference Signs List 1 n-type GaAs substrate 2 n-type GaAs epitaxial layer 3 p-type GaAs epitaxial layer 4 p-type electrode 5 n-type electrode 6, 7, 8 dicing groove 9 orientation flat

Claims (3)

[Claims] 1. A method for manufacturing a semiconductor device by manufacturing a semiconductor device by chipping a substrate on which a first conductivity type semiconductor layer and a second conductivity type semiconductor layer are stacked, comprising: The first conductivity type semiconductor layer and the second conductivity type semiconductor layer;
Forming a first groove penetrating the conductive type semiconductor layer; and opposing and not reaching the first groove from the other side of the substrate to a position corresponding to the first groove. Forming a second groove. 2. The method of manufacturing a semiconductor device according to claim 1, wherein said first groove and said second groove are formed in a direction different from a slip plane direction of a crystal constituting said substrate. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the first groove and the second groove are formed at 45 degrees with respect to a direction of an orientation flat provided on the substrate.