JPH05160047A - Vapor epitaxial growth method - Google Patents

Abstract

PURPOSE:To reduce a stress, which is remained in a wafer, and to prevent a linear defect from being generated by a method wherein the wafer is split, the split wafer pieces are put in a reaction tube as substrates for growth use and the temperatures of substrate installation parts are controlled in an extent of a specified value to epitaxially grow a III-V compound semiconductor layer. CONSTITUTION:A 2-inch diameter wager cur from an Fe-doped semi-insulating single-crystal InP ingot in (100)-plane is cut along a B-B' line (the direction parallel to an orientation flat) and a C-C' line (the direction to intersect orthogonally the orientation flat) to split into 4. These split wafer pieces are installed on a susceptor 3 of a vapor growth device and an InP layer is epitaxially grown at a growth temperature of 650 deg.C to 700 deg.C by an MOCVD method. In such a way, the areas of the substrates for growth use are made small, whereby a stress which is remained in the wafer can be reduced. Moreover, as the growth temperature is rather high, the residual stress can be released.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epitaxial growth technique, and in particular, it is used for epitaxially growing a group III-V compound semiconductor layer such as InP (indium phosphorus) by MOCVD (metal organic chemical vapor deposition). And suitable technology.

[0002]

2. Description of the Related Art VPE method (vapor phase epitaxial growth method) and M are used as epitaxial growth technology for compound semiconductors.
OCVD method and MBE method (molecular beam epitaxial method) are known. Among them, the MOCVD method has good film thickness controllability and is suitable for mass production, and is therefore used for epitaxial growth of III-V group compound semiconductor layers. FIG. 1 shows the outline of a compound semiconductor vapor phase growth apparatus.
That is, in this vapor phase growth apparatus, a plurality of source gases introduced into the reaction tube 2 by the manifold 1 flow down toward the substrate 4 mounted on the barrel type susceptor 3,
The substrate heated by the high frequency coil 5 is thermally separated to grow an epitaxial layer on the substrate.

[0003]

Conventionally, by the MOCVD method using the above-described vapor phase growth apparatus, the growth temperature (substrate installation portion) is 625 ° C., the furnace pressure is 76 torr, the H ₂ (hydrogen gas) flow rate is 10 l / min, and III. Under the general growth condition of the ratio of group source gas to group V source gas (V / III) of 250, when an InP layer is epitaxially grown on a Fe-doped InP semi-insulating substrate, the peripheral edge of the substrate is formed. Thus, there is a problem that linear defects A as shown in FIG. 2 occur on the surface of the epitaxial layer at several places.

The present invention has been made in view of the above problems, and its purpose is to prevent the generation of linear defects when epitaxially growing a III-V compound semiconductor layer on a semiconductor substrate. It is to provide a vapor phase epitaxial growth method that can be prevented.

[0005]

Means for Solving the Problems The present inventors have found that MOCV
InP on Fe-doped InP semi-insulating substrate by D method
We thought that the cause of the linear defects on the surface when the layer was grown epitaxially was the stress remaining in the wafer, and various experiments were conducted under the growth conditions that could reduce this residual stress. Some of the results are shown in Table 1.
Shown in. The residual stress is generated in the wafer because the dopant element causes strain in the crystal lattice.

[Table 1]

From Table 1 above, although a linear defect occurs even if the growth temperature is increased with a wafer having a diameter of 2 inches, the wafer is divided into four and the growth temperature is increased (650 ° C., 700 ° C.).
It can be seen that the linear defects do not occur when the temperature is set to (° C.) and the growth is performed. The present invention has been made based on the above findings, in a vapor phase epitaxial growth method of growing a compound semiconductor layer using a metal organic vapor phase epitaxy method on a substrate arranged in a reaction tube, the wafer is divided into Is put into a reaction tube as a substrate for growth, and the temperature of the substrate installation part is controlled to 650 ° C. or higher and 700 ° C. or lower to epitaxially grow the III-V group compound semiconductor layer.

[0007]

According to the above-mentioned means, since the wafer is divided and used as a growth substrate, the area is reduced, so that the stress remaining on the wafer is reduced and at the same time,
Since the growth temperature is set higher than the conventional one, residual stress of the wafer is released, and as a result, it is possible to prevent the generation of linear defects on the surface of the epitaxial growth layer.

[0008]

EXAMPLE A wafer having a diameter of 2 inches cut from an Fe-doped InP semi-insulating single crystal ingot along the (100) plane of the crystal, and this wafer were cut along the line BB ′ (parallel to the orientation flat in FIG. 2). Direction) and a CC ′ line (direction orthogonal to the orientation flat) and cut into four pieces. The wafer and the divided wafer pieces are set on the susceptor 4 of the vapor phase growth apparatus shown in FIG. 1, and the growth temperature (substrate setting part) is 620 ° C., the pressure in the furnace is 76 torr, H ₂ (hydrogen) by MOCVD. Gas) flow rate 10 l / min, and the ratio of group III source gas to group V source gas (V / III) 250, InP
The layer was grown epitaxially. Also, only the growth temperature is 7
The temperature was set to 00 ° C., and the other conditions were the same as above, and InP layers were epitaxially grown on the 2-inch wafer and the divided wafer piece, respectively.

Further, with respect to the divided wafer pieces, an experiment was conducted in which the growth temperatures were set to 600 ° C. and 650 ° C. and the InP layers were epitaxially grown under the same conditions as above. When the wafer surface after the epitaxial growth was observed, as shown in Table 1, linear defects were generated with the wafer having a diameter of 2 inches as the growth temperature was low or high. Linear defects occurred at growth temperatures of 600 ° C and 620 ° C,
No linear defects occurred when the growth temperature was 650 ° C. and 700 ° C.

In the above embodiment, Fe-doped InP is used.
The case where the InP layer is epitaxially grown on the substrate has been described as an example, but the present invention is not limited to this.
InP substrate doped with an element other than e or G other than InP
It can be applied when epitaxial growth is performed on an aAs substrate or other compound semiconductor substrate having residual stress. Further, the present invention can be used when an epitaxial layer is grown on a semiconductor substrate by a vapor phase growth method other than the MOCVD method.

[0011]

As described above, according to the present invention, in a vapor phase epitaxial growth method for growing a compound semiconductor layer on a substrate arranged in a reaction tube by using a MOCVD method, a wafer is divided to grow it. Since the substrate is placed in a reaction tube and the temperature of the substrate installation part is controlled to 650 ° C. or higher and 700 ° C. or lower to epitaxially grow the III-V compound semiconductor layer, the area of the growth substrate is reduced. The stress remaining on the wafer is reduced and the residual stress of the wafer is released because the growth temperature is set higher than before, resulting in the prevention of linear defects on the surface of the epitaxial growth layer. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a suitable vapor phase growth apparatus to which the method of the present invention is applied.

FIG. 2 shows a conventional M-layered InP layer on a Fe-doped InP substrate.
It is a top view which shows the generation condition of the linear defect of the wafer surface at the time of making it grow by the OCVD method.

[Explanation of symbols]

 1 Manifold 2 Reaction Tube 3 Susceptor 4 Semiconductor Substrate 5 High Frequency Coil 6 Support Shaft

Claims (3)

[Claims] 1. In a vapor phase epitaxial growth method for growing a compound semiconductor layer on a substrate arranged in a reaction tube by using a metal organic vapor phase epitaxy method, a wafer is divided and put into the reaction tube as a growth substrate. And a temperature of the substrate installation portion is controlled to 650 ° C. or higher and 700 ° C. or lower to epitaxially grow the III-V compound semiconductor layer. 2. The vapor phase epitaxial growth method according to claim 1, wherein the wafer for growth is formed along a direction parallel to and perpendicular to the orientation flat.
A vapor phase epitaxial growth method characterized by dividing. 3. The vapor phase according to claim 1 or 2, wherein the substrate is an Fe-doped InP substrate, and the III-V group compound semiconductor layer grown on the substrate is an InP layer. Epitaxial growth method.