JPH0267724A - Method for manufacturing compound semiconductor thin film - Google Patents

Abstract

PURPOSE:To perform a selective growth within the wide range of growth conditions with good reproducibility by a method wherein the selective manufacture of a compound semiconductor thin film using light irradiation is conducted by an organic metal chemical vapor growth method at the same time as a compound semiconductor thin film is epitaxially grown on a semiconductor substrate with a mask formed on part of its surface. CONSTITUTION:A quartz window 208 is installed on a reaction tube 206. A GaAs single crystal substrate 204 is installed on a susceptor 205 and is heated by a high-frequency oscillator 207. Group III raw materials of an organic metal trimethylgallium and an organic metal trimethylaluminum are put in bubblers 211 and 212, are introduced in the tube 206 using hydrogen gas 210 as a carrier and are epitaxially grown on the substrate 204, and group V raw materials of a hydride and an arsine 213 are introduced in the reaction tube 206 and are epitaxially grown on the substrate 204. Simultaneously, ultraviolet light from an excimer laser 201 is made to pass through an optical system 202 and is irradiated on the whole surface of the substrate through the window 208. An SiO2 film is formed by patterning on the substrate surface and an AlGaAs thin film is grown only on the exposed surface of the GaAs substrate. In the case of a group II-VI, a group VI hydride and a group II-VI organic metal addition substance or group II organic metal and a VI organic compound are used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for selectively growing compound semiconductor thin films.

[Conventional technology]

Conventionally, this is one of the methods for selectively manufacturing a compound semiconductor thin film on a semiconductor substrate, which includes means for forming a mask on a part of the semiconductor substrate, and forming a compound semiconductor thin film on the semiconductor substrate on which the mask is formed. means for epitaxial growth;
In the method for producing a compound semiconductor thin film that includes means for irradiating light during epitaxial growth, there is no limitation on the epitaxial growth method.

[Problem to be solved by the invention]

However, with conventional techniques, depending on the growth method, a sufficient selectivity ratio cannot be obtained and speckle-like crystal growth occurs on the mask, and the temperature range, light intensity range, growth pressure, etc. that allow selective growth are narrowed. It had problems such as being easy to store and having poor reproducibility. The present invention is intended to solve these problems, and its purpose is to provide a growth method that allows selective growth with good reproducibility over a wide range of growth conditions.

[Means to solve the problem]

In order to solve the above problems, the method for manufacturing a compound semiconductor thin film of the present invention includes: (1) means for forming a mask on a part of the semiconductor substrate;
A method for selectively producing a compound semiconductor thin film, including means for epitaxially growing a compound semiconductor thin film on the semiconductor substrate on which the mask is formed, and means for irradiating light during the epitaxial growth, wherein the epitaxial growth method is an organometallic chemical vapor deposition method. It is characterized by being a phase growth method.

(2) The method is characterized in that the raw materials for the organometallic chemical vapor deposition method are a group (Ⅰ) organic metal and a group V hydrogen compound.

(3) The method is characterized in that the raw materials for the organometallic chemical vapor deposition method are a group (Ⅰ) organic metal and a group (Ⅰ) organic compound.

(4) The method is characterized in that the raw materials for the organometallic chemical vapor deposition method are a group (I) group (III) adduct organometal and a group ((I) hydride).

〔Example〕

FIG. 1 is a manufacturing process diagram showing a selective growth method for a compound semiconductor thin film in an embodiment of the present invention. A dielectric film (102) is formed on a single crystal semiconductor substrate (101) (the first
Figures (a), (b)). Next, (102) is removed by etching, leaving it in an arbitrary shape (FIG. 1(C)).

Next, a compound semiconductor layer (105) is epitaxially grown on this substrate, and at the same time, the entire surface of the substrate is irradiated with light (104) (FIG. 1(d)). As a result, epitaxial growth occurs on the surface of the substrate from which the dielectric film of the mask has been removed, and selective growth is possible without the formation of deposits on the patterned dielectric film (103).

FIG. 2 shows a basic configuration diagram of a growth apparatus using a metal organic chemical vapor phase method (hereinafter referred to as MOCVD method) for selectively growing an AlGaAs thin film in an embodiment of the present invention. A quartz window (208) is installed in the reaction tube (206), and a (203)
) Light irradiation becomes possible. (205) on the susceptor (
204) A GaAs single crystal substrate is installed, and the substrate temperature is maintained by a high frequency oscillator (207). The Group Ⅰ materials of Ga and AI are TMG (trimethyl gallium) and TMA.
(21
1), the raw material in the bubbler (212) is introduced into the reaction tube using (210) hydrogen gas as a carrier. The group V raw material uses AsH3 (arsine), which is a hydride, and (
(209) into the reaction tube (206),
204) is epitaxially grown on the substrate. At that time, at the same time, the ultraviolet light from the excimer laser (201)
202), it becomes a parallel beam and is uniformly irradiated onto the entire surface of the substrate. On the surface of the GaAs substrate, 5i02
The film is formed in a pattern, and as shown in Figure 1(d), A, 1J is applied only to the exposed part of the GaAs layer.
It becomes possible to grow GaAs thin films.

FIG. 3 shows a basic configuration diagram of a growth apparatus using the MOCVD method for selective growth of an InP thin film in an embodiment of the present invention. Basically, it is the same as in Figure 2, and organic metal TMI is used as the group III raw material.
(2) (limethylindium) is placed in the bubbler (302), and the hydride PH3 (phosphine) is supplied to the V group raw material from the cylinder (303). Ajl above
As in the case of GaAs, only the exposed parts of InP that are not covered by the mask on the (301) InP substrate are
It becomes possible to grow nP thin films.

FIG. 4 shows a basic configuration diagram of a growth apparatus using the MOCVD method for selectively growing a Zn5e thin film in an embodiment of the present invention.

Basically, it is the same as in Figure 2, and H2 of hydride is added to the group II raw material.
Se (hydrogen selenide) was supplied from a (403) cylinder, and DMZn-DMSe, an organometallic adduct, was used as a group II raw material.
Adduct (dimethylzinc/dimethylselenium adduct) (
402) from the bubbler. The adduct suppresses addition reaction between DMZn and H2Se before reaching the substrate.

As in the case of AΩGaAs above, (401)GaAs
The Zn5e thin film can be grown only on the exposed portions of GaAS not covered by the mask on the substrate.

FIG. 5 shows a basic configuration diagram of a growth apparatus using the MOCVD method for selectively growing a ZnSSe thin film in an embodiment of the present invention. Basically, it is the same as shown in Figure 2, and the organic metal D is added to the group
MZn (502) is used in a bubbler, and organic compounds DMSe and DMS (dimethyl sulfur) are used as group II raw materials.
is fed into bubblers (503) and (504). As in the case of AJ7GaAs described above, (501)Ga
It is possible to grow a ZnSSe thin film only on the exposed portions of GaAs that are not covered by the mask on the As substrate.

Table 1 shows the growth results depending on the difference in growth temperature between the growth method of the present invention and other growth methods. Those for which selective growth was possible were marked as ○, and those that deposited also on the mask or those whose film quality was poor even after selective growth were marked as ×. However, GaAs1
In the case of M, the mask is a 5i02 film. In addition, all were irradiated with ultraviolet light of I W / cj during growth.

As shown in Table 1 and above, the MOCVD method, which is the growth method of the present invention, allows selective growth at a lower temperature than other growth methods. Next, similar experiments were conducted with different intensity of irradiation light, and the results are shown in Table 2. However, the growth temperature is 500°C.

As shown in Table 2 and above, in the MOCVD method of the present invention, the growth temperature is 50
At 0°C, selective growth was possible from a low light irradiation intensity of 0.4 W/cd. When the IOW/cd was reached, the surface morphology was poor and the film quality deteriorated in all growth methods.

In addition, ■-■ group compound semiconductors containing all possible combinations of mixed crystals such as InP-based and GaAs-based, and Zn
Similar results were obtained for the ■-■ group compound semiconductors containing all growable combinations of mixed crystals such as S-based, Zn5e-based, CdTe-based, etc., and MOCVD was capable of selective growth in the widest range of conditions.

〔Effect of the invention〕

As described above, according to the present invention, by using the MOCVD method as the epitaxial growth method, it becomes a lower temperature process than the chemical growth method, and the characteristics of other elements are not deteriorated in device applications. Furthermore, even at low growth temperatures, the light irradiation intensity can be set low enough to not damage the substrate, so high quality compound semiconductor thin films can be selectively grown. In addition, the MOCVD method allows for uniform growth over a large area, and has superior batch-to-batch reproducibility compared to other growth methods, so when applied to device processes, it can reduce costs and simplify work.
It has the following effects.

[Brief explanation of the drawing]

FIGS. 1(a) to 1(d) are manufacturing process diagrams showing a selective growth method for a compound semiconductor thin film in an embodiment of the present invention. FIG. 2 is a basic configuration diagram of an AJGaAs thin film growth apparatus in an embodiment of the present invention. FIG. 3 is a basic configuration diagram of an InP thin film growth apparatus in an embodiment of the present invention. FIG. 4 is a basic configuration diagram of a Zn5e thin film growth apparatus in an embodiment of the present invention. FIG. 5 is a basic configuration diagram of a ZnSSe thin film growth apparatus in an embodiment of the present invention. (101) ・ ・ ・ (102) ・ ・ ・ (103) ・ ・ ・ Single crystal semiconductor substrate Dielectric film Dielectric film remaining in pattern Irradiation light Compound semiconductor thin film Optical system Irradiation light Susceptor Reaction tube Exhaust system Hydrogen cylinder 3 or &P pot 3o2-TM t s1η゛)- 3'3 p'H3; Shout A≦Tough-D Flash Z＾ba)゛)- ()MSmutl"7'ノ- りM5B'y"')-

Claims (4)

[Claims] (1) means for forming a mask on a part of the semiconductor substrate;
A method for selectively producing a compound semiconductor thin film, including means for epitaxially growing a compound semiconductor thin film on the semiconductor substrate on which the mask is formed, and means for irradiating light during the epitaxial growth, wherein the epitaxial growth method is an organometallic chemical vapor deposition method. A method for producing a compound semiconductor thin film, characterized by using a phase growth method. (2) The method for producing a compound semiconductor thin film according to claim 1, wherein the raw materials for the metalorganic chemical vapor deposition method are a group III organic metal and a group V hydrogen compound. (3) A method for producing a compound semiconductor thin film, characterized in that the raw materials for the organometallic chemical vapor deposition method are a group II organic metal and a group VI organic compound. (4) The method for producing a compound semiconductor thin film according to claim 1, wherein the raw materials for the organometallic chemical vapor deposition method are a group II group VI adduct organometal and a group VI hydride.