JPH0742296B2 - Method for producing organozinc compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an organozinc compound comprising a dialkylzinc (hereinafter abbreviated as R ₂ Zn) and an adduct of dialkylsulfur (hereinafter abbreviated as R ₂ S). Regarding manufacturing method.

More specifically, it relates to a method for producing an organozinc compound comprising an adduct of R ₂ Zn and R ₂ S, which is effective as a raw material for MO-CVD, which is a technique for producing semiconductor thin films and semiconductor devices.

[Outline of Invention]

The present invention relates to a blue light emitting diode, zinc sulfide (ZnS) which is a material for a thin film EL element, and an organic zinc compound which is a raw material of a MO-CVD method effective for producing a mixed crystal thin film thereof, in which R ₂ Zn
By mixing with R ₂ S and forming an adduct of R ₂ Zn and R ₂ S with high purity and reproducibility by reaction and aging, H ₂ S can be compared with conventional R ₂ Zn. Or, it has low reactivity to hydrides such as H ₂ Se, and mixing of raw materials, which has been a problem in the conventional MO-CVD method, does not easily cause an unnecessary pre-reaction that occurs in the upstream of the substrate. The present invention provides a method for producing a mixed crystal thin film, and thus a raw material, which enables realization of a high-performance semiconductor device.

[Prior art]

Conventionally, in the production of ZnS and its mixed crystal thin film by the MO-CVD method, dimethyl zinc: Zn (C
H _{3) 2,} diethylzinc: using Zn (C ₂ H ₅₎ organozinc compounds such as _2, hydrogen sulfide: H ₂ S and hydrogen selenide: Atsuta customary to react with H ₂ Se. The chemical reaction when these raw materials are used is represented by the following formula.

(CH ₃ ) ₂ Zn + H ₂ S → ZnS + 2CH ₄ … (C ₂ H ₅ ) ₂ Zn + H ₂ S → ZnS + 2C ₂ H ₆ … But these reactions are because R ₂ Zn is active. When a raw material gas is introduced into the MO-CVD reactor, the reaction proceeds in the gas phase at the same time as the hydride is mixed with the hydride, and ZnS fine particles are generated before the raw material reaches the substrate surface. The quality of the crystals obtained was not so high because it adversely affected the growth process on the surface of the thin film growth substrate.

Conventionally, as means for solving these problems, (1) mixing R ₂ Zn and H ₂ S immediately before the substrate (for example, J. Cryst, Growth
59 , p1. (1982)), (2) Reduce the pressure to increase the gas flow rate (for example, Jpn.J.Appl.Phys. 22 , L583 (1983)), and other equipment system measures, and ( 3) Use zinc raw material as R ₂ Zn
In place of, an adduct obtained by equimolar mixing of R ₂ Zn and R ₂ S is used (Proceedings of the 45th JSAP Academic Lecture Meeting, P633 (1984) Lecture No. 12p-S-4), etc. Measures using raw materials have been studied.

[Problems and Objectives to be Solved by the Invention]

The MO-CVD method based on the above-mentioned conventional technique has the following problems in terms of manufacturing method and application to devices, and a solution thereof has been desired.

Compared with the prior arts (1) and (2): 1. Uniformity in thin film thickness, composition, dopant distribution, etc. is difficult to obtain because of mixing just before the substrate.

2. It is difficult to process a large area and a large number of substrates, and mass productivity is poor.

3. The quality of the crystal is poor and the emission and conduction properties cannot be controlled.

For example, in the conventional manufacturing method, R ₂ Zn and H ₂ S are mixed and sprayed at a distance of ˜2 cm from the substrate, and the size of the substrate that can be processed by this is 20 mm in diameter at most. Atsuta

Moreover, the obtained crystal has many defects, and a low-resistance film that can be used as a current element is not obtained even if it is doped with a donor impurity which is necessary when manufacturing a light-emitting diode. It was the actual situation. (Extended Abstructs o
f the 15th Conference on Solid State Devices and M
aterials 1983 pp349, B-7-8, wherein) the reactivity with the 1.R ₂ Zn and R ₂ S with respect to the prior art (3) not very high, simply by mixing equimolar amounts of both, the following equation R ₂ Zn + R ₂ S → R ₂ Zn-SR ₂ reaction of could not be completed, and physical properties such as vapor pressure of the obtained product
The variation was large, depending on the mixing conditions, the history of use until the reaction, etc.

2. Also, as a result, when the ZnS epitaxial growth is performed by reacting with H ₂ S by MO-CVD method using the adduct obtained by mixing the equimolar amounts as a raw material, the growth rate of the epitaxial thin film and its physical properties The reproducibility was bad.

The object of the present invention is to solve such problems, the reactivity with H ₂ S or H ₂ Se hydride as a Zn raw material is lower than that of R ₂ Zn, and the gas phase reaction at room temperature can be suppressed, and MO -By using as a Zn raw material in the CVD method, it is possible to grow a good quality thin crystal film on a large area and on a large number of sheets, and by doping impurities,
Another object of the present invention is to provide a method for producing a high-purity organozinc compound that has desired light emission characteristics and electrical conductivity and that realizes device-level crystal quality with good reproducibility.

[Means for solving problems]

The method for producing an organozinc compound of the present invention comprises: a) adding the dialkylzinc and the dialkylsulfur so that the low-boiling point component of the dialkylzinc and the dialkylsulfur becomes excessive with respect to the high-boiling point component of the A step of mixing, a) a step of heating the mixture of the dialkylzinc and the dialkylsulfur mixed in the step a), and c) an excess amount with respect to the amount of the high boiling point component after the step a). And a step of distilling and removing the low boiling point component.

In the step a), the dialkylzinc and the dialkylsulfur are mixed with the dialkylzinc such that the molar amount of the low-boiling component is 1.1 to 1.2 equivalent to the molar amount of the high-boiling component of both. It is characterized in that the dialkyl sulfur is mixed.

In addition, the step of heating the mixture is a step of reacting at 0 ° C to 40 ° C for 10 minutes to 3 hours, a step of gradually raising the temperature, 30 ° C to
It is characterized by comprising a step of aging at 80 ° C. for 10 minutes to 2 hours.

Table 1 summarizes R ₂ Zn and R ₂ S applicable to the present invention, but it is obvious that this is not the case.

Adducts of R ₂ Zn and R ₂ S is a R ₂ Zn as an electron acceptor, and R ₂ S as an electron donor, one-to-one acid - those resulting from the base reaction, wherein R ₂ It consists of the structure of Zn-SR ₂ . As a method for producing the adduct, it is possible in principle even by mixing equimolar amounts of the respective components,
(Procedures of the 45th Annual Meeting of the Japan Society of Applied Physics, P633 (1984), Lecture No. 12p-S-4), in order to complete the reaction and produce an adduct with highly pure and reproducible physical properties, A process is required.

R ₂ Zn and R ₂ S are mixed with each other in excess of the low-boiling point component, preferably, the low-boiling point component to the high-boiling point component are mixed at a ratio of 1.1 to 1.2 equivalents, and both are the boiling point of the low-boiling point component or less. At about 0 to 40 ° C for 10 minutes to 3 hours, preferably 10 to 35 ° C for 1 to
Allow to react thoroughly for 2 hours.

After that, to complete the reaction, gradually raise the temperature to 30-80 ° C.
The temperature is raised for 10 minutes to 2 hours, preferably 10 to 15 ° C./hour, and aged at 30 to 70 ° C. for 30 minutes to 1 hour.

Finally, excess components are removed by distillation.

The formation of the adduct can be confirmed by the following facts.

(1) Heat is generated by mixing the two.

(2) The vapor pressure-temperature curve of the produced adduct is different from that of R ₂ Zn and R ₂ S as the starting materials.

(3) The reaction takes place at a ratio of R ₂ Zn and R ₂ S of 1: 1 due to the charged amount of the raw materials, the amount of the product and the excess distillate component.

(4) Analysis by NMR The organozinc compound according to the present invention and the method for producing the same will be described below with reference to Examples.

Example 1 (CH ₃ ) ₂ Zn—S (C ₂ H ₅ ) ₂ 300 ml round bottom flask was charged with 109.5 g (1.2166 mol) of S (C ₂ H ₅ ) ₂ and (CH ₃ ) ₂ with stirring. Zn122.0 g (1.279 mol) was added dropwise with a dropping funnel to react. The reaction was exothermic and the amount of heat generated was large.

The reaction temperature was controlled at 10 to 15 ° C and the reaction was carried out for 1 hour. Thereafter, the temperature was gradually raised at a rate of 10 ° C./hour and aged at 38 ° C. for 30 minutes. After that, unnecessary excess was distilled off by distillation. The product weighed 227 g.

FIG. 1 shows the vapor pressure-temperature characteristics of the obtained adduct. The horizontal axis is temperature and the vertical axis is vapor pressure.

The solid line is the adduct and the broken line is the raw material S (C _2
2 shows vapor pressure characteristics of H ₅ ) ₂ and (CH ₃ ) ₂ Zn.

FIG. 2 shows the signal by the proton of the methyl group of (CH ₃ ) ₂ Zn of the product by NMR.

The chemical shift of the product is δ = -0.60 ppm,
₃ ) ₂ Zn has a single component of δ = −0.67ppm, so (C
H ₃₎ showed the formation of _{2 Zn-S (C 2 H} 5) 2 adduct.

Moreover, the variation between the lots having different physical properties such as vapor pressure characteristics was less than the detection. In addition, the results of NMR also showed that there was no single component of (CH ₃ ) ₂ Zn which was the raw material, and the purity was extremely high.

Example 2 _{(C 2 H 5) 2 Zn} -S (C 2 H 5) in the same manner as Example ₂ 1 round bottom flask _{300ml, S (C 2 H 5} ) 2 5
Charge 6.3 g (0.6255 mol) and stir (C ₂ H ₅ ) ₂ Zn7
5.4 g (0.611 mol) was added dropwise and reacted. The reaction was exothermic and the amount of heat generated was large.

The reaction temperature was controlled at 35 to 40 ° C and the reaction was carried out for 2 hours. After that, the temperature was gradually raised, and the temperature was raised to 45 ° C., followed by aging for 1 hour in a natural state. Next, unnecessary excess was distilled off by distillation. The product weighed 130 g.

FIG. 1 shows the vapor pressure of the adduct obtained in the solid line. The dashed lines indicate the vapor pressures of the raw materials S (C ₂ H ₅ ) ₂ and (C ₂ H ₅ ) ₂ Zn, respectively.

Generate Example 3 _{(CH 3) 2 Zn-S} (CH 3) 2 Likewise S (CH ₃₎ substantially equivalent or less of a ₂ (CH ₃₎ above adduct by a ₂ Zn can be dropped reacting did. The solid line in Fig. 1 is the adduct, and the broken line is the raw material for each S (CH ₃ ).
₂ shows vapor pressures of ₂ and (CH ₃ ) ₂ Zn.

Example 4 _{(C 2 H 5) 2 Zn} -S (CH 3) 2 In the same manner, to produce the adduct with S (CH _{3) 2} and a _{(C 2 H 5) 2 Zn} . The solid line in FIG. 1 shows the vapor pressure of the adduct.

Table 2 exemplifies the vapor pressures of the organozinc compounds comprising the adduct of R ₂ Zn and R ₂ S according to the present invention with respect to typical temperatures.

Next, using the adduct obtained in the above example, MO at normal pressure was used.
-When ZnS crystalline thin films were formed on GaAs and GaP substrates by CVD equipment, good quality single crystalline thin films were obtained with any of the adducts. The flow of cloudy particles accompanying the pre-reaction of R ₂ Zn and H ₂ S in the gas phase, which occurred at the same time as the conventional mixing, and the deposition of particles upstream of the thin film growth substrate were not observed.
The adduct based on the present invention and H ₂ S were mixed in advance with He gas as a carrier and then introduced into the post reaction tube, and then introduced from the introduction port to 20
Since a ZnS single crystal thin film with a smooth surface condition was obtained on the GaAs and GaP single crystal substrates placed at a position 0 mm apart, the adduct according to the present invention suppresses the pre-reaction and improves the productivity. It became clear that it had a great effect. Also, Al, Ga, C
By doping with donor impurities such as l and I, n-type conductivity with a specific resistance of 0.1 to 1 Ωcm was obtained after the growth.
In addition, strong blue light emission of 470 nm was obtained by irradiating ultraviolet rays with a wavelength of 250 to 350 nm from a xenon lamp. These facts show that the crystal formed by using the organozinc compound according to the present invention has high quality. Further, the adduct according to the present invention has the following effects as compared with the conventional adduct obtained by simply mixing the same molar amount.

(1) Physical properties of a crystalline thin film using the same bubbler, in particular, resistivity, emission wavelength, and changes in device characteristics such as emission wavelength and intensity in manufacturing a light emitting diode using the crystal over time Almost none, and the variation was extremely small.

(2) Even when the adducts having different lots were used, the variation was extremely small.

〔The invention's effect〕

As described above, according to the present invention, R ₂ Zn and R ₂ S are excessively mixed with low-boiling components of both, and after reaction and aging by heating, excess components are distilled off. Due to
R ₂ Zn and R ₂ with high purity and reproducibility of physical constants such as vapor pressure
It has the effect of providing an organozinc compound consisting of an adduct of S.

From this, it is convinced that the role of the present invention is great for manufacturing not only blue light but also visible light emitting diodes, semiconductor lasers, thin film EL elements and the like.

[Brief description of drawings]

Fig. 1 shows the vapor pressure-temperature characteristics of organozinc compounds, ...... Temperature, ・ ・ ・ Vapor pressure …… (CH ₃ ) ₂ Zn-S (C ₂ H ₅ ) ₂ , …… (C ₂ H ₅ ). ₂ S ...... (CH ₃ ) ₂ Zn, …… (C ₂ H ₅ ) ₂ Zn-S (C ₂ H ₅ ) ₂ …… (C ₂ H ₅ ) ₂ Zn, …… (CH ₃ ) ₂ Zn- _{S (CH 3) 2 ...... (} CH 3) 2 S, ...... (C 2 H 5) 2 Zn-S (CH 3) 2 Figure 2 is a signal diagram ...... TMS by proton product methyl group, ... … Product …… Chemical shift …… Signal strength

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Teruyuki Mizumoto, Inventor Teruyuki Mizumoto, 3-3-5 Yamato, Suwa City, Nagano Stock Company, Suwa Seikosha Co., Ltd. (72) Masao Fujisawa, 3-1-1 Katsuma, Hofu, Yamaguchi Prefecture (72) Inventor Akihiro Ichikawa 287-155 Tokuyama, Tokuyama City, Yamaguchi Prefecture

Claims (3)

[Claims] 1. A) The dialkylzinc and the dialkylsulfur are added such that the molar amount of the low-boiling point component of the dialkylzinc and the dialkylsulfur becomes excessive with respect to the molar amount of the high-boiling point component of the both. Mixing step, a) heating the mixture of dialkylzinc and dialkylsulfur mixed in step a), and c) an excess amount after the step a) with respect to the amount of the high boiling point component. And a step of distilling and removing the low boiling point component. The method for producing an organozinc compound comprising an adduct of dialkylzinc and dialkylsulfur having: 2. The dialkylzinc and the dialkylsulfur so that the low-boiling point component of the dialkylzinc and the dialkylsulfur has a 1.1 to 1.2 equivalent ratio to the high-boiling point component of the both in the step a). The method for producing an organozinc compound according to claim 1, characterized in that 3. The step of heating the mixture comprises 0 ° C. to 40 ° C.
For 10 minutes to 3 hours, a step of gradually raising the temperature,
The method for producing an organozinc compound according to claim 1 or 2, comprising a step of aging at 30 ° C to 80 ° C for 10 minutes to 2 hours.