JPS6236808A - Manufacture of semiconductor hetero junction - Google Patents

Abstract

PURPOSE:To obtain a semiconductor hetero junction which consists of two kinds of semiconductors different in lattice constant and is lattice-conformed without crystal defects, by forming a set of specified thin layers between the first semiconductor and the second semiconductor. CONSTITUTION:At least one set of the set 3, which consists of a thin layer 32 with the number of thickness + Angstrom of the second semiconductor and a thin layer 31 with the number of thickness + Angstrom of the first semiconductor, is inserted between the first semiconductor layer 1 and the second semiconductor layer 2. The lattice constant of the set of those semiconductor layers is gradually altered from the side adjoining the first semiconductor 1 to the side adjoining the second semiconductor 2. That is to say the thickness of layer of the thin layers 32 and 31 is gradually decreased from the first semiconductor layer 1 to the second semiconductor layer 2 as for the first semiconductor thin layer 1 and is gradually increased from the first semiconductor layer 1 to the second semiconductor layer 2 as for the second semiconductor thin layer 32.

Description

[Detailed Description of the Invention] [Summary] Two types of semiconductors having different lattice constants (a first semiconductor and a second semiconductor) have different lattice constants.
This is a method for manufacturing a lattice-matched semiconductor heterojunction consisting of a semiconductor of

Between the first semiconductor layer and the second semiconductor layer, a combination of a thin layer of the second semiconductor with a thickness of about several tens of nanometers and a thin layer of the first semiconductor with a thickness of about several tens of nanometers is provided. The lattice constant of this set of semiconductor thin layers is gradually changed from the side close to the first semiconductor to the side close to the second semiconductor, and the lattice constant of this set of semiconductor thin layers is The lattice constant of the first semiconductor is made to approach the lattice constant of the second semiconductor from the lattice constant of the first semiconductor.

[Industrial application field]

The present invention relates to a method for manufacturing a semiconductor heterojunction. In particular, the present invention relates to a method for manufacturing a lattice-matched semiconductor heterojunction made of two types of semiconductors having different lattice constants.

[Conventional technology]

Conventionally, in order to form a semiconductor heterojunction using two types of semiconductors with different lattice constants, a single layer of eight fibers having a lattice constant between the lattice constants of the two types of semiconductors was interposed. . A buffer layer used for such purposes is often obtained by changing the mixed crystal ratio when one or both of the two types of semiconductors are compound semiconductors, but it is On the other hand, it is clear that a semiconductor having a lattice constant in between (a semiconductor suitable as a buffer layer) does not necessarily exist.

[Problem that the invention seeks to solve]

When a suitable semiconductor cannot be obtained as a single layer of eight layers,
There is no choice but to manufacture a heterozygote with lattice mismatch.

Even in such cases, if the upper layer semiconductor is formed sufficiently thick, the lattice mismatch itself can be cured, but crystal defects that occur at the lattice mismatch interface tend to continue to grow, so generally the layer thickness is Even if you make it thicker, it does not necessarily disappear. Therefore, when using two types of semiconductors with different lattice constants, it is not easy to manufacture a semiconductor heterozygote that is lattice matched and free of crystal defects. It has been desired to develop a method for manufacturing a semiconductor heterojunction free of crystal defects.

An object of the present invention is to meet this demand, and to provide a method for manufacturing a semiconductor heterojunction that is lattice-matched and free of crystal defects and is made of two types of semiconductors having different lattice constants.

[Means for solving problems]

The means taken by the present invention to achieve the above object are as shown in FIG. So, a. Between the two semiconductor layers 1 and 2, there is a thin layer 32 of the second semiconductor with a thickness of about several tens of amps, and a thin layer 31 of the first semiconductor with a thickness of about several tens of amps. At least one set 3 is included, and the thickness of the thin layers 32 and 31 forming this set is the same as that for the first semiconductor thin layer 31 from the first semiconductor layer 1 to the second semiconductor layer 31.
The thickness of the second semiconductor thin layer 32 is gradually increased from the first semiconductor layer 1 to the second semiconductor layer 2.

[Effect]

When thin films 4.5 of two types of condensing substances with lattice constants a and aB are formed in contact as shown in Fig. 2, the lattice constants of these thin films 4.5 are both expressed by the following formula: As shown in , the lattice constants a and a of the two types of crystalline substances are
The intermediate value a. It is known to change to B.

however, f is the lattice mismatch degree, d　, dB are the respective crystalline substances ^ The film thickness is G, G8 are respective crystalline substances It is a new car.

The present invention takes advantage of this property, and as shown in FIG. At least one set 3 of a thin layer 32 of approximately the thickness of the first semiconductor and a thin layer 31 of the first semiconductor having a thickness of several tens of layers is included, and the lattice constant of the set 3 of the semiconductor thin layers is set to be the same as that of the first semiconductor l. It is designed to gradually change from the side closer to the second semiconductor 2 to the side closer to the second semiconductor 2.

〔Example〕

Hereinafter, a method for manufacturing a semiconductor heterojunction according to an embodiment of the present invention will be further described with reference to the drawings.

Refer to Fig. 3 PbTe substrate-L with P b T e o , s e
The case of forming the Seo, 04 layer will be described.

The lattice constant of PbTe is 6.46, and P b T
e o, 9e S e o, o i.

The lattice constant of is 8.448, and lattice matching cannot be achieved if these are brought into direct contact. Therefore, PbTe substrate 1
and PbTeSe layer 2, between PbTe layer 31 and PbT
Five sets (3a, 3b, 3c, 3d, 3e in order from the one closest to the PbTe substrate 1) with the eSe layer 32 were provided, and the thickness of each layer was as shown in the table below.

3 a 20 803 b
40 803 c 50
503 d 130
403e8020 was grown using the normal HWE method.

When the PbTe-PbTeSe heterozygote produced as described above was observed using an optical microscope with a magnification of 2,000 times, no abnormal growth was observed at all.

By the way, PbTeS with the above mixed crystal ratio was deposited on a PbTe substrate.
When a similar inspection method was applied to a heterozygote in which the e-layer was directly grown, approximately 10'' abnormal growths were observed per lc+a.

〔Effect of the invention〕

As explained above, in the method for manufacturing a semiconductor heterozygote according to the present invention, when manufacturing a heterozygote of two semiconductors (a first semiconductor and a second semiconductor) having different lattice constants, B. Between the above two semiconductor layers, at least one set of a thin layer of the second semiconductor with a thickness of about several tens of nanometers and a thin layer of the first semiconductor with a thickness of about several tens of nanometers is inserted. , the layer thickness of the thin layers forming this set is such that the thickness of the thin layer of the first semiconductor gradually decreases from the thin layer of the first semiconductor toward the layer of the second semiconductor; As for
A method for manufacturing a lattice-matched semiconductor heterojunction using a seed semiconductor can be provided.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of the present invention. FIG. 2 is a diagram explaining the principle of the present invention. FIG. 3 is a detailed explanatory diagram of the present invention. ■...First semiconductor layer, 2...Second semiconductor layer, 3. a to 3e... A set of a second semiconductor thin layer and a first semiconductor thin layer, 31... A thin layer of semiconductor 1, 32... A second semiconductor thin layer. Describing the present invention in Figure 1 (Figure 1) Figure 2 (1) Description Figure 3

Claims (1)

[Scope of Claims] A method for manufacturing a semiconductor heterojunction comprising a first semiconductor and a second semiconductor having a lattice constant different from that of the first semiconductor, comprising: the first semiconductor (1) and the second semiconductor; a thin layer of the second semiconductor (2) and the first semiconductor (2);
forming at least one set (3) with thin semiconductor layers, and the thickness of each layer constituting each of the set (3) of thin layers is as follows:
Regarding the thin layer of the first semiconductor, the thin layer of the first semiconductor (
1), the thin layer of the second semiconductor is gradually reduced in size from the side close to the first semiconductor (1) to the side close to the second semiconductor (2). A method for manufacturing a semiconductor heterojunction, characterized in that the size of the semiconductor heterojunction is gradually increased toward the side closer to the second semiconductor (2).