JPS61280609A - Hetero junction structure - Google Patents

Abstract

PURPOSE:To facilitate the formation of single crystal of groups III-V and II-VI with excellent quantity IV crystal such as Si, Ge, etc. by a method wherein a specific intermediate layer is laid in a hetero junction structure bonding IV semiconductor crystal to III-V or II-VI compound semiconductor crystal. CONSTITUTION:An intermediate layer of Ge doped with V group atom As in a thin film at high concentration is provided between Ge in V group crystal and GaAs in III-V semiconductor crystal. Numerous As atoms are exposed to the surface of intermediate layer doped with As at high concentration to be chemically bonded to Ge atoms. In such a state, when GaAs begins to grow, the probability of Ga adhesion to As exposed to the surface being overwhelmingly superior to that of As, the growing probability of one domain out of two possible domains overwhilmingly exceeds the other growing probability. Resultantly two opposing domains can be prevented from growing here and there, thus facilitating the formation of GaAs comprising single crystal.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a heterojunction structure used in the semiconductor industry.

(Prior art and its problems) In general, m-vi and ■-■ group compound semiconductors are materials that have a wide range of uses as crystals for electronic devices and optical devices; It was customary to use them in the form of bulk crystals or in the form of epitaxial crystals between them. However, these are IV
If it is possible to grow high-quality m-vi semiconductors such as GaAs or InP on silicon or germanium crystals, the design of electronic and optical devices can be improved. It is very advantageous because it has a large degree of freedom. However, it is versatile (10
0) When trying to grow GaAs etc. on silicon y (Si), it is free to choose whether Ga or Aa is attached to the 8i atoms exposed on the (100) surface, so GaAs (100) is a crystal with untied domains here and there, and its electrical properties are not necessarily good.

FIG. 2 is an example of a structural diagram when a ■-■-■ conductor crystal is directly grown on a conventional group II semiconductor crystal. In this case, germanium (Ge), l1l as the group ■ crystal
- Gallium arsenide (GaAs) was used as an example of the V group semiconductor. When a GaAs crystal grows on Ge in this way, two cases are distinguished: KAs on Ge is deposited first, and Ga is deposited first.

When growing single-crystal GaAs on this Ge, either Ga or A8 needs to be unilaterally chemically bonded to the surface of the Ge single crystal, but both Ga and As have a finite bonding probability on Ge. GaAs cannot be grown in a single phase because of this. Of course, as the number of untied phase regions increases, excess energy is accumulated at the interface between phases, so a mechanism works to prevent the number of regions from increasing indefinitely, but it is impossible to reduce the number to zero. Can not.

As a result, it is divided into regions having a certain size. In this figure, the regions indicated by phase (2) and phase (2) constitute mutually anti-phase regions. The boundary between these phase regions is a type of crystal defect, and thus becomes an obstacle when manufacturing devices and the like using this crystal.

(Objective of the Invention) The object of the present invention is to develop Peter's method that makes it possible to grow a complete single-crystal ■-V group or II-■ group crystal without such an untied domain structure on a group ■ crystal. The purpose is to provide a bonding structure.

(Structure of the Invention) The structure of the present invention includes a group ■ semiconductor crystal and a group ■-V or II group semiconductor crystal.
- In a petrojunction structure that combines a compound semiconductor crystal of the ■group, the above-mentioned
−■ Group high crystal heterojunction is provided as an intermediate layer, and the above-mentioned ■
When a heterojunction is made between a group crystal and the n-■s crystal, a thin film group III crystal doped with a high concentration of a group III or group III and having a thickness of at least a monoatomic layer is provided as an intermediate layer. do.

(Example) Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a diagram of a joining structure of an embodiment of the present invention.

In this example, Ge of the group II crystal and G of the m-va semiconductor crystal are used.
It is shown that an intermediate layer of 9Ge doped with a thin film of Ast, a group II atom, is sandwiched between the aAs and the aAs.

Since this intermediate layer is doped with a high concentration of As, a large amount of As is exposed on the surface of the intermediate layer, and this As is chemically bonded to Ge atoms. G in this state
Once the growth of a A s starts, the probability that Ga will adhere to As exposed on the surface is overwhelmingly greater than the probability that As will adhere, so one of the two possible domains The growth probability is overwhelmingly large, reaching 4. Therefore, the growth of two opposing domains here and there is inhibited and the formation of a single coherent GaAs is facilitated.

Note that the present invention can be applied to a single G based on the same principle even if Ga-doped Ge is used instead of As in FIG.
An aAs layer can be obtained. In addition, InP is used instead of GaAs, and P-doped or In is used instead of As-doped Ge.
Doped Ge allows the existence of a single crystal of InP on Ge. In this case, the l-V group may be a mixed crystal, and the single crystal growth of the ■-■ group instead of the ■-■ group is also possible based on the same principle.

(Effect of the invention) As explained above, according to the present invention, Si.

On group II crystals such as Ge, QaAs, Ink, I
nAs.

GaInP, Zn5e, ZnS, Zn5e
8th class ■-■ group.

It becomes possible to easily form a high-quality single crystal of the ■-■ group.

[Brief explanation of drawings]

FIG. 1 is an atomic arrangement diagram of a heterojunction structure according to an embodiment of the present invention, showing the presence of single crystal GaAs on a Ge single crystal via a thin interlayer of Ge doped with a high concentration of As. , FIG. 2 is an atomic arrangement diagram of an example of a conventional heterojunction structure, showing GaAs separated into two phases on a Ge single crystal.

Claims (1)

[Claims] In a heterojunction structure that combines a group IV semiconductor crystal and a group III-V or group II-VI compound semiconductor crystal, the group IV crystal and the group III-V crystal are heterojunctioned at the interface between these two crystals. In this case, a thin film group IV crystal doped with a group III or V element at a high concentration and having a thickness of at least a monoatomic layer is provided as an intermediate layer, and the group IV crystal and the group II-VI crystal are heterojunctioned. In this case, a heterojunction structure characterized in that a thin film group IV crystal doped with a high concentration of group II or VI and having a thickness of at least a monoatomic layer is provided as an intermediate layer.