JPH0258215A - Manufacture of compound semiconductor thin-film - Google Patents

Abstract

PURPOSE:To obtain a method, in which III-V and II-VI compound semiconductor thin-films are epitaxial grown under the conditions of a low substrate tempera ture at a free composition ratio, by epitaxially growing the compound semicon ductor thin-films onto a semiconductor substrate, to which a mask is formed, and irradiating light during the epitaxial growth. CONSTITUTION:As a method in which compound semiconductor thin-films 105 are manufactured selectively onto a semiconductor substrate 101, a mask 103 is shaped to one part on the semiconductor substrate 101, and the compound semiconductor thin-films 105 are epitaxially grown onto the semiconductor substrate 101, to which the mask 103 is shaped, while light 104 is applied during the epitaxial growth. A dielectric film 102 is formed onto the GaAs single crys tal substrate 101, and the dielectric film 102 is removed through etching while being left to an arbitrary shape. The GaAs layers 105 are epitaxially grown onto the substrate 101, and the whole area of the substrate is irradiated with light 104 at the same time. When light 104 is not applied, polycrystalline GaAs or granular GaAs is grown, and the method is difficult to be applied to a device.

Description

[Detailed description of the invention] [Industrial application field 1 The present invention relates to a method for selectively growing compound semiconductor thin films.

[Prior art 1 A conventional method for selectively growing Ill-V group compound semiconductor thin films such as GaAs and A-flooded GaAs is described in the Journal
Crystal Growth (Journal of Crys)
tal Growth) Vo 1. 73
．． (1985) P73-P76, chemical vapor deposition method (hereinafter referred to as MOCV) using organic metals as raw materials
In the case of method D), a dielectric film such as 5fNx was formed in a pattern on a GaAS single crystal substrate, and the reaction pressure was low (denoted as method D), and the substrate temperature was high.

In addition, methods for selectively growing Ill-V group compound semiconductor thin films such as InP are described in Applied Physics Letters.
) V o l.

47 (1985) As seen in PI 127 to P1129, chloride vapor phase epitaxy c or less loride VPE
It was obtained by forming a dielectric film of 5iO= or the like in a pattern on an InP single crystal substrate using a method (hereinafter referred to as "method").

In addition, the selective growth method of II-Vl group compound semiconductor thin films such as Zn5e is described in the Proceedings of the Japan Society of Applied Physics (Autumn 1988, 18a-x-9). A dielectric film such as SiO□ was formed in a pattern, and the reaction pressure was low and the substrate temperature was high.

[Problem to be Solved by the Invention 1] However, in the case of selective growth of GaAs in the above-mentioned conventional technology, a high substrate temperature of 650°C or higher is required, making it difficult to apply it to semiconductor lasers and optoelectronic integrated circuits (hereinafter referred to as 0EIC). In this case, there was a problem in that the characteristics of other functional elements and the active layer were deteriorated. In addition, in the case of selective growth of AffGaAs, a high substrate temperature of 700°C or more is required.
Afi composition X of AI2oG a + -x A s is 0
．． There was a problem in that selective growth of 35 or more could not be obtained.

Since a thin film with a large AR composition cannot be selectively grown, thin films with arbitrarily different energy gaps (hereinafter referred to as Eg) cannot be obtained, and therefore the range of application is limited.

In addition, in selective growth of InP etc., chloride VP
Since E is used, a compound semiconductor thin film containing Aff such as y A I I n P cannot be grown, and there is a problem in that it is impossible to grow a thin film having a large Eg and luminescent properties.

Also, selective growth of II-Vl group compound semiconductors such as Zn5e requires a high substrate temperature of 600°C or more.
There was a problem in that instability such as Zn diffusion occurred at the interface between the GaAs substrate and the Zn5e thin film, which deteriorated the characteristics of other functional elements formed on the substrate.

The present invention is intended to solve these problems, and its purpose is to form +11-V group and II-Vl group compound semiconductor thin films in free composition ratios under conditions of low substrate temperature. An object of the present invention is to provide a manufacturing method that allows epitaxial growth.

[Means for Solving the Problems 1] The method for manufacturing a compound semiconductor thin film of the present invention includes means for forming a mask on a part of the semiconductor substrate in a method for selectively manufacturing a compound semiconductor thin film on a semiconductor substrate; The present invention is characterized in that it includes means for epitaxially growing a compound semiconductor thin film on a semiconductor substrate on which a mask is formed, and means for irradiating light during the epitaxial growth.

[Function 1] According to the above configuration of the present invention, by performing light irradiation during epitaxial growth, the adsorbed molecules absorb the light energy before a deposit is formed on the mask, and are re-introduced into the gas atmosphere. On the surface of the semiconductor substrate not covered by the mask, where the evaporation occurs and no deposition occurs on the mask, a crystal layer having good properties even at low temperatures is grown by light irradiation. Therefore, selective growth is possible at low substrate temperatures. Furthermore, if the wavelength of the irradiated light is appropriately selected, the adsorbed molecules on the mask can be re-evaporated when forming mixed crystal thin films such as AffGaAs and Aj2InP, making it possible to select mixed crystal thin films with arbitrary compositions. growth becomes possible.

[Example] The present invention will be further explained in detail based on Examples.

FIG. 1 is a manufacturing process diagram showing a selective growth method for a GaAs thin film in an embodiment of the present invention. A dielectric film 102 is formed on a GaAs single crystal substrate 101 (Fig. 1(a)).
, (b)), then etching is removed leaving 102 in an arbitrary shape (FIG. 1(c)). Next, 102 is etched on this substrate.
A GaAs layer of No. 05 is epitaxially grown, and at this time, the entire surface of the substrate is irradiated with light of No. 104 at the same time (Fig. 1 (d)). Epitaxial growth occurred, and no deposit was obtained on the patterned dielectric film 103.6 If the light irradiation 104 was not performed, polycrystalline GaAs or granular GaAs would grow on 103. This makes it difficult to apply to devices. A similar phenomenon occurs in ARGaAs, InP
.

This also occurred during the growth of various compound semiconductors such as Zn5e and ZnS, and good selective growth was possible.

FIG. 2 shows a basic configuration diagram of a growth apparatus using the MOCVD method in the case of selective growth of an AεGaAS thin film in an embodiment of the present invention. A quartz window 208 is installed in the reaction tube 206 so that light 203 can be irradiated.

A GaAs single crystal substrate 204 is placed on a susceptor 205, and the substrate temperature is maintained by a high frequency oscillator 207. Ga and A9. The raw materials are trimethyl gallium (hereinafter referred to as TMG) and trimethyl aluminum (hereinafter referred to as TMG).
Each raw material in cylinders 216 and 217 is introduced into the reaction tube using hydrogen gas as a carrier. Arsine (hereinafter referred to as A s Hs) gas is introduced into the reaction tube from the cylinder 209 and epitaxially grown on the substrate 204 . At the same time, ultraviolet light from an excimer laser 201 passes through an optical system 202 to become a parallel beam and uniformly irradiates the entire surface of the substrate. A SiO□ film was formed in a pattern on the surface of the GaAS substrate, and as shown in Figure 1(d), it was possible to grow an AβGaAs crystal thin film only on the exposed GaAS surface. . Selective growth was performed at a low substrate temperature of 300° C. to 600° C., and a crystal with good crystallinity and strong band edge emission could be obtained even at low temperature growth. FIG. 3 shows a basic configuration diagram of a growth apparatus using a molecular beam epitaxy method (hereinafter referred to as MOMBE method) using an organic metal as a raw material in the case of selective growth of a GaAs thin film in an embodiment of the present invention.

A quartz window 303 is installed in the ultra-high vacuum container 305, and a heater 307 for heating the substrate is installed inside. 31
305 TMG, ASH3 from 3,314 gas sources
At this time, ultraviolet light emitted from an excimer laser 301 is irradiated onto the surface of the substrate 306 through an optical system 302. On the substrate 306, an Si02 film is formed in a pattern as shown in FIG. 1(c). As shown in Figure 1(d), Ga
It was possible to grow a GaAs crystal thin film only in areas where the As surface was exposed. Selective growth was performed at a low substrate temperature of 300° C. to 600° C., and a crystal with good crystallinity and strong band edge emission could be obtained even at low temperature growth. By the same method as described above, GaAs-based and InP-based III-V
All combinations of mixed crystals that can be epitaxially grown in group compound semiconductors can be selectively grown at low substrate temperatures, and Zn5e, ZnS, etc. I-V
Selective growth was possible at low substrate temperatures for all combinations of mixed crystals that can be epitaxially grown in group I compound semiconductors.

[Effects of the Invention] As described above, the present invention has the following effects.

(1) Compound semiconductor thin films can be selectively grown at low substrate temperatures, so if used in optical devices or OEICs, they can be used for important purposes such as device planarization without deteriorating the characteristics of other functional elements or active layers. Can run processes.

(2) Since it is possible to selectively grow mixed crystal thin films in almost any combination by light irradiation, it is possible to grow into any shape by controlling Eg. Therefore, it becomes possible to form a low-loss leading waveguide by using a short-wavelength emitting material for buried growth, and to realize 0EIC using a short-wavelength semiconductor laser.

(3) By light irradiation, the crystallinity of the epitaxially grown thin film is improved compared to the conventional thin film grown at low temperature, and it is possible to form a functional element as it is. Therefore, it has the effect of simplifying the process of optical devices and 0EICs and improving reliability.

(4) MOCVD method or MOMBE method can be used, and selective growth can be performed with a uniform film thickness over a large area.

[Brief explanation of the drawing]

FIGS. 1(a) to 1(d) are manufacturing process diagrams showing one embodiment of the method for manufacturing a compound semiconductor thin film of the present invention. FIG. 2 is a basic configuration diagram of a manufacturing apparatus showing an embodiment of the compound semiconductor thin film manufacturing method of the present invention. FIG. 3 is a basic configuration diagram of a manufacturing apparatus showing an embodiment of the compound semiconductor thin film manufacturing method of the present invention. 101... Single crystal semiconductor substrate 102.
......Dielectric film 103...Dielectric film 104 left in a pattern shape...Irradiation light 105... ...Compound semiconductor thin film 201.
301... Ultraviolet light source 202.302...
...Optical system 203.304...Ultraviolet light 204.306...Substrate 205...Susceptor 206...
...Reaction tube 207... ...High frequency power supply 208.303
...Quartz window 209.210.314.313 ...Raw material source 211-215, 311-312 ...Mass flow controller 216.217 ...Bented metal 218-223, 228,229...Valve 224.309...Turbo molecular pump 225.
226.310・・Lokuri pump 227・・・・
・・・・Abatement device 305・・・・・・・・・・Reactor 307・・・・・・・・・・・・・・・ Above the substrate heating peak Applicant: Seiko Epson Corporation

Claims (1)

[Claims] A method for selectively manufacturing a compound semiconductor thin film on a semiconductor substrate, comprising means for forming a mask on a part of the semiconductor substrate, means for epitaxially growing a compound semiconductor thin film on the semiconductor substrate on which the mask is formed, and during the epitaxial growth. A method for producing a compound semiconductor thin film, comprising: a means for irradiating light.