JPS6095919A - Semiconductor element and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent any crystalline defect from happening in a nitrogen-doped n<-> grown layer by a method wherein nitrogen and neutral impurity with larger atomic radius than that of nitrogen having no influence upon impurity concentration is added to an n<->GaP grown layer. CONSTITUTION:A boat comprising a member containing a GaP substrates 12 and GaP solution 17 is mounted in a main furnace. Firstly after heating the main furnace up to specified temperature, a Ga.GaP solution reservoir 18 is shifted in the arrow B direction to drain Ga.GaP solution containing Si and Al in a member 11 forming an n<+> grown layer doped with Si and Al on the substrate 12. Secondly when a reactor is filled with Ar+NH3 gas, an n<-> grown layer with N in the form of GaN added thereto is formed on the N<+> grown layer. At this time, Al with larger atomic radius than that of N is trapped in a distorted crystal part due to smaller atomic radius of N than that of P to prevent any crystalline defect from happening. Successively p<+> grown layer may be continuously formed on the n<+> grown layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a semiconductor device and a method for manufacturing the same, and particularly to a compound semiconductor device for a GaP light emitting device.

[Technical background of the invention and its problems]

Generally, a compound semi-vertical element used for a GaP light-emitting element, for example, a GaP green light-emitting element, has an N
Type GaP substrate 1. Place the GaP substrate 7. Jl, J) High concentration of first N-type C3aPN4 (hereinafter referred to as

n called growth layer')2. A second N-type GaP layer with a lower a degree than the OaP substrate 1 (hereinafter referred to as an n-growth layer)
3. and GaP substrate 1 υ high elf P-type GaP
Layer C (hereinafter referred to as p+ growth layer) 4 is manufactured by continuous liquid phase growth. The compound semiconductor device manufactured in this manner generally contains hole-shaped crystal defects 5.5 called voids, as shown in FIG. In particular, many of the crystal defects 5, 5, etc. generated in the n- growth layer 3Vc penetrate the PN junction with the p+ growth layer 4.
When a green light emitting element was manufactured, the brightness deteriorated after being energized.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide a semiconductor element with fewer crystal defects and a method for manufacturing the same, in which a multilayer GaP growth layer is formed on a GaP substrate.

[Summary of the invention]

This invention relates to a plurality of GaP substrates formed on a GaP substrate.
Among the growth layers, we focused on the fact that crystal defects were concentrated in the GaP growth layer (n-growth layer), which had the same conductivity type as the GaP substrate and had a lower concentration than the GaP % board12, and found that the cause was the n-growth layer. This was done based on the discovery that this was due to the dopant contained in the layer. In other words, the inventors discovered that the atomic radius of N (nitrogen), which is commonly used as a dopant for the n-growth layer, is different from that of other GaP growth layers (n
+ growth layer, p+ growth layer, etc.) dopant (
For example, it is smaller than the atomic radius of Ga and P in the substrate (Si, Zn) and GaP.
We discovered that when (nitrogen) replaces P in GaP by 1d, a difference in atomic radius causes a shift in the growing crystal, and when the degree of shift exceeds the limit, crystal defects occur]
.

Ta. Therefore, in this invention, in addition to N (nitrogen), a neutral impurity having an atomic radius larger than that of N and having no effect on impurity transition is added to the n- growth layer. This aims to reduce crystal defects.

[Actual example of invention]

Refer to the drawings for an embodiment of the present invention1. I will explain.

Figure 3 (al is a sectional view along the longitudinal direction of the boat for liquid phase epitaxial growth, Figure 3 (bl is a cross-sectional view of Figure 3 (al)
It is a sectional view along the -Y line. These Figures 3 (al,
(In BL, 11 accepts a carbon storage member 12,
GaP curtain plates 12, 12, . . . are placed on the bottom thereof. As shown in FIG. 4, the upper opening of the storage member 11 has first openings 13, 13... and second openings 14, 14...
・A large carbon lid 15 is provided to cover the ears. In addition, FIG. 3 (al is a sectional view I corresponding to the Y'-Y' line in FIG. 4. Also, the part indicated by the broken line in FIG. 4 is a GaP% plate (12°12...) This corresponds to the carbon large lid 15 (storage member 11) and the Ga
The planar positional relationship with P1 & plates (1212...) is shown. Along the longitudinal direction of the carbon large lid 15, it is slidably installed approximately on its center line, and a spout 1 is provided at the bottom.
A Ga/GaP solution reservoir member 18 having a diameter of 6.16 and accommodating a Ga solution 17 and a GaP solution 17 inside is provided. This Ga, GaP solution 17 contains Ga, Gar (poly) which follows the saturation of Oa, Sr (silicon) which is a dopant of the n+ growth layer, and N (nitrogen) with an atomic radius.
It consists of a neutral impurity similar to Ga, P, for example, a trace amount of AI (aluminum).
a.P.

The atomic radius (specifically, the tetrahedral covalent φ bond radius) of Si, N, Zn, and AJ is shown.

GaP substrate 12.12 also uses the ports listed above in the table below.
A specific example of performing liquid phase growth of Ga and GaP on... This figure 5 shows Ga
FIG. 6 is a cross-sectional view of the boat showing the state after a GaP solution is poured onto a GaP substrate, and FIG. 6 is a diagram of a heating program during liquid phase epitaxial growth.

(1) First, in the reactor consisting of a main furnace and an auxiliary furnace, the main furnace K G'a P substrate 72 , 12-= and Ga.

Contains GaP solution 17 1. The boats consisting of parts t and + were each set with Zn crucibles in the auxiliary furnace.

After this, the inside of the reactor was evacuated [,,l); After confirming that there was no leakage, hydrogen (Hl) gas was introduced at a flow rate of 901/H.
Flow into the reactor at 1. ．． and start raising the temperature of the main furnace. When 30 minutes have elapsed since the main furnace has become uniformly heated (1000° C.) (point a in FIG. 6), slide the Ga, OaI' solution reservoir member 18 in the direction of arrow B in FIG. The GaP
The pouring ports 16, 16,... of the solution reservoir ladle 18 are aligned with the second openings 14, 14,... of the carbon dimple 15, respectively, and are accommodated in the ladle 18 (Si and Al
)Ga.

The GaP solution 17 is poured into the storage member 11 (see FIG. 5). Next, Ga, GaP molten night gathering member 1
After returning 8 to the original position fJ+', hold the main furnace at 1000℃ for 120 minutes12, OaP Q plate 12.
At the same time, the loaded Ga solution is baked.

After an appropriate amount of 8i donor and 1 volume of AI were released into the Ga solution by the reducing action of H and gas, the temperature was lowered to 970°C (point b in Figure 6) 122, and the GaP substrate 12°12... was placed on top of it. High concentration doped with Si and AI (4X10I7
cm-") to form an n++ long layer.

fill Next, while flowing H as a carrier gas and A gas instead of gas, a mixed gas based on Ar gas (Ar+NH) is flowed into the reactor.The NH3 concentration at this point is 0. After starting to flow these gases, the main furnace was kept for 120 minutes (also. During this time, Si in the Ga solution reacts with NH as follows, forming nitrides Si, N, form.

3 SI + 4NHB ;=! Si3N4+
51(.

In addition, NH, reacts with Ga solution as follows to form GaN.
It solidifies in the form of (gallium nitride).

2Ga + 2NHs: 2GaN + 3H.

Even in this Ga solution, the A7 component remains [2] although the silage rate is small due to the formation of the n+ growth layer. After this, the inside of the main furnace was
When the temperature is lowered to ℃ (point C in Figure 6), G is formed on the n++ long layer.
A low donor concentration (0
,8X 10"cf" ~1.5XIQIllcm
! ) n-growth @ (low a degree GaP growth layer) is formed. During the growth of this n- growth layer, the atomic radius of N (nitrogen) is smaller than that of P (P(+)n in GaP). A large AJ (aluminum) quadrupole is used to prevent the formation of crystal defects called voids. This Ad (
Aluminum) is a neutral impurity that cannot serve as either a donor or an acceptor, and does not affect the concentration of the n- growth layer or the like.

oril Next, the auxiliary furnace was heated to 720℃ and one product was heated to Z
The acceptor impurities are supplied to the main furnace by converting n into a vapor state.

On the other hand, after holding the main furnace at f930°C for 100 minutes 12 and sufficiently eluting Zn into the Ga solution on the previous 8e n-growth layer,
(xr-1-NH3) Stop the supply of mixed gas and heat to 750°C.
temperature decreases to (point d in Figure 6) [2nd n+ 537 long layer,
The n- growth layer and the p+ growth layer formed continuously
A compound semiconductor device for aP green light emitting device is obtained.

However, 11, the acceptor a of the p++ long layer is, for example, 6 x
It may be in the range of 1017α-3 to 3×10I8cIn-3.

In addition, in the previous 6-Pyrolysis Example, a dopant for preventing the occurrence of crystal defects and 1. Al was used in this study, but any impurity that has a 1 m radius larger than N and is neutral is sufficient).

〔Effect of the invention〕

Detailed explanation above 1. According to the present invention, in particular, N (nitrogen) doped low concentration change GaP growth can be used for semiconductor devices in which a plurality of OaP growth layers are formed on GaP 8 plates, such as compound semiconductor devices for GaP green light emitting devices. layer (n-growth layer)
It is possible to reduce crystal defects (voids) that occur in the process.

[Brief explanation of drawings]

Figure 1 is a diagram of GaP compound semiconductor for green light emitting device (a
1 is a cross-sectional view of a boat for liquid phase epitaxial cell growth according to the present invention;
Figure 4 is a cross-sectional view along the line, Figure 4 is a plan view of the carbon large lid shown in Figures 3(a) and (bl), Figure 5 is the state after pouring Ga and GaP solutions onto the GaP substrate. The cross-sectional view of the port shown in FIG. 6 is a temperature program diagram during liquid phase epitaxial growth. 11... Storage member, 13... First opening portion, 14...
・Second opening, 15... Carbon large lid, 16... Note, outlet, 17-Ga, GaP solution, 1B-C) a, Ga
P solution reservoir member. Applicant's agent Patent attorney Takehiko Suzue Figure 4 15 Figure 5 Figure 6

Claims (1)

[Scope of Claims]
1. A semiconductor device comprising a plurality of GaP growth layers doped with nitrogen and a neutral impurity having an atomic radius larger than that of the nitrogen at a low concentration on a substrate. 121 0aP A storage member in which a substrate is stored, a lid provided at the upper opening of the storage member and having a plurality of openings, a pupil slidably provided on the lid, and a spout at the bottom, Ga, G with predetermined dopants added inside
Using a liquid phase epitaxial growth port made of an aP solution reservoir member, this G
In order to sequentially liquid-phase grow a plurality of GaP growth layers including a low concentration GaP growth layer that has the same conductivity type as the aP substrate and has a lower concentration than the GaP substrate, the above Ga, Ga, P solution and [7] nitrogen A semiconductor device manufacturing method characterized by using a Ga, GaP solution to which a predetermined dopant containing a neutral impurity with a large atomic radius is added, and using a gas containing NH3 when forming the low-temperature #'GaP growth layer. Method.