JPS63205921A - Manufacture of optical semiconductor element - Google Patents

Abstract

PURPOSE:To obtain a good p-7 junction interface so as to obtain good blue emission, by using a semiconductor element manufacturing method where light radiation is performed when a p-type layer grows. CONSTITUTION:Organic compound or hydride is used as group II and VI raw materials, and Al compound or chlorine compound is used as a n-type impurity raw material, and NH3 is used as a p-type impurity raw material, and a n-type II-VI compound semiconductor layer and a p-type II-VI compound semiconductor layer are laminated. At that time, the n-type II-VI compound semiconductor layer is manufactured by a vapor growth method of conventional heat decomposition. The p-type II-VI compound semiconductor layer is formed by a vapor growth method accompanied by light radiation, for example, excimer laser beam radiation of 350 nm or less in wavelength. Thereupon, since the light is not radiated during n-type growth, decomposition of remaining NH3 does not occur. Thus, a good p-n junction interface is obtained so as to obtain good blue emission.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application vf) The present invention relates to a method for manufacturing an optical semiconductor device using a ■-■ group compound semiconductor.

(Prior art) ZnS, Zn8e, Zn5xSe1-x(0(x(1)
■-■ group compound semiconductors such as blue LED or blue L
It is expected to be a D material. The most important issue in realizing blue LED devices lies in the 4-type control of these materials.

Western et al. used LI as a p-type impurity raw material to form a p-n junction element using a liquid phase growth method under vapor pressure control, and obtained blue light emission (J, Appl, Phys, 57).
61°1985).

However, since this is a high-temperature liquid phase growth method, it has the drawback that the interface characteristics of the p-n junction are poor and it is difficult to obtain a large-area crystal. Furthermore, there are disadvantages in that the process steps involved in forming the pn junction are complicated, and reproducibility is difficult to obtain.

In order to overcome these drawbacks, metal organic vapor phase epitaxy (M
OCVD) is being studied. This means that for Zn5e, organometallic compounds such as dimethylzinc (DMZ) are used as the group ■ raw material, and dimethyl selenium (DMZ) is used as the group ■ raw material.
It uses an organic compound such as S e ) or a hydrogen compound such as hydrogen selenide. Regarding n-conduction control,
Triethylaluminum (kL (C
*Hs) 3) By incorporating At into the site of the group II element (Patent application 1986-051429),
Alternatively, this can be achieved by using hydrogen chloride (He t ) as an impurity raw material and incorporating chlorine (CA) into the site of the Group I element (Japanese Patent Application No. 59-054173). p
Regarding type conduction control, it has been shown that by using NH as the impurity raw material and incorporating N into the group II group, a shallower acceptor level than K is formed (W, 5t).
utiusAppl, Phys, Latt, 40(3
) 246).

By this conventional MOCVD method, n-type Zn5e was grown on the GaAs substrate, and NH,p was grown on it.
Even if Zn5e is grown as a dust impurity raw material and a p-n junction is formed, the properties of the junction interface are very poor, and the blue light emission is
Not obtained. This is because the thermal decomposition temperature of NH is high, so the growth temperature must be raised in the conventional MOCVI) method. Therefore, interdiffusion of Ct% in the n-type layer and N in the p-type layer and generation of Se and Zn vacancies occur, resulting in deterioration of the characteristics of the bonding interface.

(Problems to be Solved by the Invention) As mentioned above, in the conventional liquid phase growth method under vapor pressure control, defects are likely to occur due to high temperature growth, and large-area crystals cannot be created. , the interface characteristics of the p-n junction are poor;
Furthermore, there is a problem that the process of forming the pn junction is complicated.

In addition, in the conventional MOCVD method, NH, is used as a p-type impurity raw material to form a p-n junction, reducing the growth temperature, increasing the area of the crystal, and simplifying the process of forming the p-n junction. However, there was a problem in that the interface characteristics of the p-n junction were poor and blue light emission could not be obtained.

The present invention has good p-n junction and interface characteristics.
An object of the present invention is to provide a method for manufacturing an optical semiconductor device using a group compound semiconductor.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, a method for manufacturing an optical semiconductor device using a group I-Ⅰ compound semiconductor according to the present invention will be described below.

An organic compound or hydride is used as a raw material for group III and group III, an aluminum compound or a chlorine compound is used as a raw material for n-type impurities, and ammonia (NHs) is used as a raw material for p-type impurities.
In a method for manufacturing an optical semiconductor device in which an n-type layer - group II compound semiconductor layer and a p-type layer - group II compound semiconductor layer are laminated using A p-type layer - a group compound semiconductor layer is formed by a vapor phase growth method accompanied by light irradiation, for example, excimer laser light irradiation with a wavelength of 350 nm or less, and stacked.
This is a method for manufacturing an optical semiconductor element in which a pn bond is formed.

(Function) In this method of manufacturing an optical semiconductor device using a group 1I-VI compound semiconductor, when p-type layers are laminated, the decomposition of NH3 in the gas phase or surface adsorption phase is promoted by light energy, and the decomposition of NH3 is accelerated at low temperatures. Since N is doped efficiently, a good p-type layer and pn junction are formed.

(Example) FIG. 1 is a schematic diagram of an apparatus for carrying out the method of the present invention. In this figure, inside the reaction tube (101) is a substrate (
106) is housed on the susceptor (105). The susceptor (105) is heated by a heater (not shown), and the substrate (106) on the susceptor (105) is set to a predetermined temperature. Into the reaction tube (101'), an organometallic compound, which is a group material, is introduced from a gas inlet (103).
Organic compounds or hydrogen compounds, which are group raw materials, and carrier gas, and HC, which is an n-type impurity raw material, in the case of n-type growth.
When the t gas grows p-type, NH, which is the n-type impurity raw material,
3 gases are introduced. In addition, when growing p-type, the reaction tube (1
01) and on the substrate (106) are excimer lasers (
Laser light (109) from 108) is irradiated through the synthetic quartz introduction window (107). In addition, a light introduction window (10
7) To suppress film formation on the gas inlet (10
4) Inject hydrogen gas or inert gas into the reaction tube (101
) is introduced within.

From the gas inlets (103) and (104) to the reaction tube (1
01) Exhaust system (102) that exhausts the gas introduced into the interior
By adjusting the pumping speed of the reaction tube (101), the pressure inside the reaction tube (101) is set to a predetermined pressure. A method for manufacturing an optical semiconductor device using a reaction tube configured in this manner will be described below.

Dimethylzinc (hereinafter referred to as DMZ, !: abbreviated) is used as the raw material for the group ■, dimethyl selenium (hereinafter referred to as DMSe) is used as the raw material for the group ■, and DMZ and DM8 e(7) dP-? Hydrogen gas was used as the rear gas. The substrate also includes p-type Ga.
ArF (λ=193r1m) light was used as the irradiation light introduced into the As substrate during pm growth.

In addition, HCz, which is an n-type impurity, has a pace of 20 (N) pmHs, and NH, which is a p-type impurity, has a pace of 1010001
)p! I used the base.

First, first pass the hydrogen gas 200 through the gas inlet (104).
SCCM is introduced into the reaction tube (101), and the exhaust system (1
02) and set the pressure inside the reaction tube (101) to 56 torr. Then the susceptor (105
) was heated, and the p-type GaAs substrate (106) on the susceptor (105) was set at 450°C. Next, the gas inlet (1
03) Yoshi, DMZ, DMSe, -? −? Riff, //
Hydrogen gas and NH3 gas are transferred to the reaction tube (101).
At the same time, the excimer laser (108) irradiates ArF excimer laser light having a wavelength of 193 nm vertically onto the substrate (106) through the light introduction window (107).
Type Zn5e/i was grown. The supply amount of each raw material gas, carrier gas, NH, and gas is DMZ: 3.5xlOr
rpl/1I161. DM8e: 7. OX
The settings were 10 mOL/m, DMZ carrier gas (hydrogen gas) 39 SCCM, DMSe carrier gas (hydrogen gas) 1008 CCM, and NH3 gas 30 SCCM. The irradiation energy of the ArF excimer laser beam on the surface of the substrate (106) was 1 mJ/-, and the number of irradiation edges was s.
o pps. Next, the supply of NH and gas and the light irradiation were simultaneously stopped, and HCt gas was introduced into the reaction tube. The HCt gas was set at 200 SCCM, the gas pressure in the reaction tube was kept at 50 torr, and the substrate temperature was kept at 450° C. to grow an n-type Zn5e layer.

The pn junction created in this manner exhibited good diode characteristics and produced true color light emission.

In the above example, the substrate temperature was set at 450°C, but the range of the substrate temperature (Ts) may be 400°C≦Ts≦700°C, and the set temperature for NFI growth and p-type growth may be different. In addition, in the above example, the ratio QHC7/QvI of the supply amount QHC□ of HCt gas and the supply 1 t (Qvl) of the group II raw material DM8e is set to 2-55X1.
Although it was set to 0-2, the supply ratio QHc, /QvI0 value is
10-4≦Q HR/Q! It is sufficient if it is in the range of +≦10−1. Also, NH.

The ratio QN1/QvI of the gas supply amount (,QNH-) and the supply amount (Q,) of group II raw material DMSe was set to 1.9X10-2, but the value of the supply ratio QNH1/Qvl was 10-5≦
It is sufficient if it is in the range of QNH3/Q kidney 10-1.

Furthermore, the irradiation energy (PI) of the laser beam on the substrate surface
The repetition frequency of the light per l pulse was set to p 1 mJ/, i, and v-sa, but the repetition frequency was set to so pps.
The range of laser beam irradiation energy (Pl) is 10”mJ
/ad≦P and ≦5 nmJ/−, and the repetition frequency of the laser beam may be other than so pps.

Note that the present invention is not limited to the embodiments described above, and can be modified and implemented without departing from the gist thereof. The film to be grown is not limited to Zn8e semiconductor, but also Zn.
S, Zn5xSe1-x(0(x(1) and other ■-
A group compound semiconductor may also be used. In addition, the raw material gas is DMZ,
Not limited to DM8e, other organometallic compounds or hydrides may be used. The light irradiated during p-type growth is not limited to ArF excimer laser light, but also 1571m, 222nm, 248nm.
m1308f1m, 3501'Excimer laser light with a wavelength of 1m or less may be used, or a low pressure mercury lamp, Xe-
A bright line generated by a Hg lamp or a rare gas microwave discharge may be used.

Furthermore, the GaAs substrate used for growth may have other plane orientations and is not limited to p-type, and may also have other 11-type substrates such as GaP.
l-V group compound semiconductors, Zn5e, ZnS.

A ■-■ group compound semiconductor such as CdTe or ZnTe may also be used. Alternatively, after growing an n-type layer, a p-type layer may be grown to form a pn junction.

〔Effect of the invention〕

Using the method of manufacturing an optical semiconductor device according to the present invention in which light irradiation is performed when growing a p-type layer (because even if the n-type layer is grown after the p-type layer is grown, the light is not irradiated during the n-type growth, No decomposition of residual NH occurred, a good p-n junction interface was obtained, and good back-color emission was obtained.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a reaction tube for explaining one embodiment of the present invention. 101... Reaction tube, 102... Exhaust system, 103...
・Gas inlet, 104...Gas inlet, 105...
Susceptor, 106...GaAs substrate, 107...Light introducing window, 108...Excimer laser, 109...Excimer laser light. Agent Patent Attorney Nori Chika Yudo Kikuo Takehana

Claims (6)

[Claims] (1) Using an organometallic compound as a group II raw material, an organometallic compound or a hydrogen compound as a group VI raw material, and ammonia (NH_3) as a p-type impurity raw material, an n-type II-VI group compound semiconductor layer and a p-type II- In a method for manufacturing an optical semiconductor device formed by laminating Group VI compound semiconductor layers, the n-type II-VI compound semiconductor layer is formed by a vapor phase growth method using thermal decomposition, and the p-type II-
1. A method for manufacturing an optical semiconductor device, comprising forming and laminating a Group VI compound semiconductor layer by a vapor phase growth method involving light irradiation. (2) Claim 1, characterized in that the light irradiated is excimer laser light with a wavelength of 350 nm or less.
A method for manufacturing an optical semiconductor device as described in Section 1. (3) The Group II raw material is dimethylzinc (Zn(CH_3)
_2), or diethylzinc (Zn(C_2H_5)_2
), the Group VI raw material is dimethylselenium (Se(CH_3)_2) or diethylselenium (Se(C_2H_5)_2) as a selenium (Se) raw material, dimethylsulfur (S(CH_3)_2) or 2. The method for manufacturing an optical semiconductor device according to claim 1, wherein the material is diethyl sulfur (S(C_2H_5)_2). (4) The II-VI group compound semiconductor is ZnSe, ZnS,
Claim 1 characterized in that it is ZnSSe.
A method for manufacturing an optical semiconductor device as described in Section 1. (5) A patent characterized in that the epitaxial substrate crystal is p-type, a p-type photoexcited growth layer doped with nitrogen is laminated thereon, and an n-type growth layer formed only by thermal dissociation reaction is subsequently laminated on this layer. A method for manufacturing an optical semiconductor device according to claim 1. (6) The epitaxial substrate crystal is made into an i or n type, and a p-type photoexcited growth layer doped with nitrogen is laminated thereon, and then an n-type growth layer formed only by thermal dissociation reaction is laminated on this layer to form a p-n A method of manufacturing an optical semiconductor element according to claim 1, characterized in that a junction is formed.