JPH0218926A - Manufacture of compound semiconductor film - Google Patents

Abstract

PURPOSE:To make it possible to obtain a Ga compound semiconductor film more excellent in quality by using at least one kind among specific compounds as a compound that includes gallium. CONSTITUTION:At least one kind among the compounds expressed by the formula of R1R2GaCp, R1Ga(Cp)2, Ga(Cp)3, GaR1R2(acac), R1Ga(acac)2, Ba(acac)3, R3R4Ga-GaR5R6 is used as a compound that includes gallium. Among the formula, R1 and R2 indicate alkyl group, substitutional alkyl group, etc., and Cp does cyclopentadienyl group, and acac does CH(R1CO)2 group or CF(R1CO)2 group, and R3-R6 do alkyl groups or halogens. Hereby, film quality, light absorbing characteristics, and selectivity of growth improve.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a -Y group compound semiconductor thin film.

[Conventional technology]

■-■ Group compound semiconductor thin film, especially Ga as a group ■ element
Those using this technology have a wide range of applications, including high-speed transistors, light-emitting devices, and light-receiving devices. GaM is being studied as a blue light emitting device because of its wide bandgap energy (14 eV). Gap,
GaAsP is applied as a light emitting element in a wide visible range from green to red. Further, GaAs is used as a microwave amplification transistor and a light emitting/light receiving element in the near infrared region by utilizing its high mobility.

Recently, as a manufacturing method for such compound semiconductor thin films, Mov
pg (organometallic vapor phase epitaxial method) and MOMBg
(Organic metal-based molecular beam fertilization method) is attracting attention as an alternative to the conventional liquid-phase fertilization method and halide VPE method. The reason for this is that these methods have good controllability and mass production, and can be used with a wide range of raw materials.

Conventionally used organometallic compounds containing Ga atoms that are controversial include trimethyl gallium (TMG) and ethyl gallium (T).
RG), but there is a problem with the contamination of impurities, which are thought to be mainly carbon, and it is desirable to improve the crystallinity of the N film in the sheath layer, improve the electrical characteristics, and improve the controllability of conductivity. Ru.

On the other hand, in order to further expand the range of application of these 9m-v group compound semiconductors, a so-called photo-selective growth technique that uses exposure operations is extremely useful. That is, by irradiating the substrate with ultraviolet light or visible light during thin film growth, effects such as lowering the growth temperature, improving thin film quality, direct buttering, and controlling conductivity are expected. Recently, Aoyagi et al. GaAs OMOVPB! We found that selective growth is possible by Ar laser irradiation [Journal Op Applied Physics (J
, Appl, Phye, ) Volume 60, Page 5131 (
1986)).

[Problem to be solved by the invention]

However, at present, there are problems in that there is a limit to the growth rate and the quality of the thin film is insufficient.

The purpose of the present invention is to provide a method for producing a Ga-based compound semiconductor thin film of higher quality, and also to improve the growth rate and thin film quality in photoselective shrimp growth.

[Means to solve the problem]

To summarize the present invention, the present invention relates to a method for manufacturing a compound semiconductor thin film, in which a compound containing gallium and a compound containing an element of group VTLJ of the periodic table of elements are introduced in a gas phase into a reaction vessel, and these are heated. In the method of manufacturing a ■-v group compound semiconductor thin film on a substrate placed in the reaction vessel by decomposition, the gallium-containing compound is represented by the following general formulas [A] to [G]: CA) R3R4GaCp (B) RIGa (mouth p
)z(a) aa(op)s (D) GaR5R
6(acaa)(K) RIGa(acac)1 (
F) Ga(acac)1(G) R3R4Ga-Ga
R5R6 (in the formula, R1 and R2 are the same or different), an alkyl group,
Substituted alkyl group, alkoxy VM, substituted alkoxy group, alkylthio group, substituted alkylthio group or halogen, Op
is a cyclobentazyl group, acac is aH (Rlao
), a group or 0F(R100), R3-R6 represent the same or different cy, alkyl group, or halogen].

The raw materials used are different from the conventional technology.

As a manufacturing method, 'FiMOVPI! f, MOMB, go
In addition, there is a MOVPK method that uses an IeOR excitation method in combination, but the method is not limited to these.

Specific names and physical property values of the compounds are shown below in a table, but the present invention is not limited thereto.

Table 1 Specific names of compounds MOVPK4-MO using these organometallic raw materials
This book was based on the discovery that when a compound semiconductor thin film is created using the MBI method, the quality of the thin film is improved compared to when using conventional raw materials, and the selectivity of growth by light irradiation is also significantly improved. This led to the completion of the invention.

At present, it is not necessarily clear why this effect is obtained. Due to the effects of new b substituents, etc., the adsorption and thermal decomposition properties on the substrate differ, and the light absorption characteristics generally shift to the longer wavelength side and become Il & 9, so that the decomposition by light irradiation improves. It is estimated that

Many of the raw material compounds used in the present invention are solid at room temperature, and many of them are vapor-containing. Therefore, during actual use, measures such as heating the raw material storage cylinder and piping system are required. Raw materials that are liquid at room temperature can be introduced into the reaction vessel by bag ring as in the conventional method.

On the other hand, examples of group VB elements in compounds containing group VB elements of the periodic table of elements used in the present invention include Fi nitrogen, phosphorus, arsenic, and antimony, and examples of compounds containing them include ammonia, phosphine, arsine, Examples include stibine and antimony trichloride.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The invention is not limited to these examples.

Example 1 FIG. 1 is a system diagram showing the configuration of an apparatus when the present invention is applied to the production of a single crystal thin film of a GaN compound semiconductor. In Fig. 1, reference numeral 1 is an organometallic compound, 2 is a bubbler container, 5 and 8 are gas flow controllers, 4 is a nitrogen gas cylinder, 5 is a heating device, 6 is a reaction vessel, 7 is an ammonia cylinder, and 9 is a substrate. , 10 is a susceptor, 11 is a thermocouple,
12 is a high frequency heating coil, and 13 is an exhaust port. In the same figure, a nitrogen gas whose flow rate is adjusted by a gas flow controller 3 is placed in a bubbler container 2 in which an organometallic compound containing Ga element (diethyiWV chlorobentadiene gallium) 1 constituting a GaN compound semiconductor is sealed. A gaseous organometallic compound is introduced into the reaction vessel 6 by flowing . At this time, the bubbler container is heated to 70° C., which is above the melting point, in order to increase the vapor pressure of the compound. On the other hand, ammonia, which is a raw material containing the nitrogen element constituting the GaN compound semiconductor, is supplied in the required amount from a cylinder 7 filled with the ammonia into the reaction container via a llL amount controller 8. A substrate 9 is placed on a susceptor 10, heated to a predetermined temperature by a high frequency heating coil 12, and a GaN thin film is formed by a chemical vapor phase reaction. Susceptor temperature is 900
to 1000°C is suitable. Created in this way, 90aN
The concentration of impurities in the thin film could be reduced by more than an order of magnitude compared to the time when conventionally known TMG was used. Furthermore, the crystallinity evaluated by X-ray diffraction was also significantly improved.

Examples 2 to 14 Ga thin films were prepared in the same manner as in Example 1, except that the compounds shown in Table 2 below were used instead of diethylcyclopentagel gallium. At this time, the bubbler container 2 is heated above the melting point of the compound. From similar evaluations, it was confirmed that high-quality thin μy could be obtained in all cases as in Example 1.

Table 2 Compounds used in Examples 2 to 14 Example 15 FIG. 2 is a block diagram of an apparatus for explaining the 15th example of the present invention, in which reference numeral 21 is a reaction vessel, 22 is a substrate, and 23 is a susceptor. , 24 is an Ar laser, 25 and 26 are gas introduction pipes, 27 is an infrared thermometer, and 28 is an exhaust port. GSL is placed on the GaAs substrate 22 installed in the reaction vessel 21.
This is an example of epitaxial growth of AII. At this time A
By irradiating the substrate with the r laser (wavelength: 514.5 nm) 24, it is possible to create a contrast between the growth of the irradiated area and the non-irradiated area. A Ga-based organometallic compound (dimethylcyclobentadienyl potassium) and an Ae-based raw material (arsine) are introduced from 25.26 in the same manner as in Examples 1 to 14, respectively. Film thickness contrast 300 at substrate temperature 500℃ and laser power 2W
It was confirmed that this was obtained. This is the conventional '1'1l
The contrast was increased by more than 5 times compared to when using iG.

Furthermore, the carbon impurity concentration was also reduced by more than an order of magnitude.

Ar laser (wavelength 35S, Onm) and Kr laser were used as light sources.
When an excimer laser (wavelength: 248 nm) was used, a significant improvement in characteristics was confirmed in the same manner as in the present invention. Furthermore, when the organometallic compounds used in Examples 1 to 14 were used, thin films with excellent characteristics were similarly obtained, and the growth contrast was also large.

〔Effect of the invention〕

As explained above, according to the method for manufacturing a compound semiconductor thin film according to the present invention, a material containing at least one new substituent or the like is used as an organometallic compound raw material containing Ga. For this reason, a significant improvement in thin film quality has been achieved, and in the photo-selective shrimp growth technology, the light absorption properties are shifted to the longer wavelength side, which has the advantage of improving the light absorption properties and significantly improving the selectivity of growth.

[Brief explanation of drawings]

Figure 1 shows GaN used in Examples 1 to 14 of the present invention.
FIG. 2 is a system diagram showing the configuration of a single crystal thin film manufacturing apparatus. FIG. 2 is a configuration diagram showing the GaAs thin film manufacturing apparatus used in Example 15 of the present invention. 1: Organometallic compound, 2: Bubbler container, 3 and 8: Gas flow controller 4 = Nitrogen gas cylinder, 5: Heating device, 6 and 21: Reaction container, 7: Ammonia cylinder %
9 and 22: Substrate, 10 and 23: Susceptor, 11: Thermocouple, 12: High frequency heating coil, 13 and 28: Exhaust port, 24: Ar laser% 25 and 26: Gas introduction pipe, 27
:Infrared thermometer

Claims (1)

[Claims] 1. Compound containing gallium in reaction vessel and element V of the periodic table
In a method for producing a III-V compound semiconductor thin film on a substrate placed in the reaction vessel by introducing a compound containing a group B element in a gas phase and thermally decomposing the compound, the compound containing gallium is as follows: General formula [A] ~ [G]: [A]
R1R2GaCp[B]R1Ga(Cp)_2[C]G
a(Cp)_3[D]GaR1R2(acac)[E]
R1Ga(acac)_2[F]Ga(acac)_3
[G] R3R4Ga-GaR5R6 [wherein R1 and R2 are the same or different, an alkyl group,
Substituted alkyl group, alkoxy group, substituted alkoxy group, alkylthio group, substituted alkylthio group or halogen, Cp is cyclopentadienyl group, acac is CH(R1CO)_2 group or CF(
R1CO)_2 group, R3 to R6 are the same or different and represent an alkyl group or a halogen. 2. The method for manufacturing a compound semiconductor thin film according to claim 1, wherein the substrate is irradiated with ultraviolet light or visible light. 3. The method of manufacturing a compound semiconductor thin film according to claim 2, wherein the light source of ultraviolet light or visible light is a laser.