JPS5812230B2 - epitaxial epitaxy - Google Patents

Description

[Detailed description of the invention] The present invention relates to a liquid phase epitaxial growth method.

GaA melt is saturated with GaAs and Gap polycrystals.
A method of growing crystals while slowly cooling a compound single crystal semiconductor substrate of S or Gap in contact with the substrate is known as a liquid phase epitaxial growth method.

FIG. 1 shows the structure of a Gap light emitting diode manufactured by this method, which includes two layers, an N-type epitaxial layer 2 and a P-type epitaxial layer 3, which are sequentially formed on an N-type cap substrate 1.

Conventionally, in order to sequentially grow such different epitaxial layers, each epitaxial layer is grown using a different melt, but in this case, after growing the first epitaxial layer, the substrate is once placed in a reactor. The second epitaxial growth is carried out after the melt is taken out and another melt is set again.

Therefore, when the substrate is taken out after growing the first epitaxial layer, undesirable impurities tend to adhere to the substrate, damaging the crystallinity of the PN junction and the second epitaxial layer, and in the case of a light emitting diode. Its luminous efficiency decreases.

The present invention has been made in view of the above-mentioned drawbacks, and it is an object of the present invention to provide a method that enables continuous growth of different epitaxial layers without requiring the substrate to be moved in and out, and is highly productive in mass production.

FIG. 2 shows a growth boat 1 used in the method according to the present invention.
shows.

The boat consists of a rectangular cylinder 2 and two upper and lower nullide plates 3 and 4.
It consists of

Each Nuride plate passes through the inside of the cylinder body 2 through insertion holes 5, 6 and 7, 8 provided in the opposing side walls of the pair of cylinder bodies 201, and the side surfaces of each Nuride plate 3, 4 are connected to the cylinder body 2. It is smoothly held in grooves cut into the inner surfaces of the other set of opposing side walls.

Furthermore, each Nuride plate 3, 4 is provided with a small hole 9.

The inside of the cylinder 2 is divided into an upper part 10a, a middle part 10b, and a lower part 10c by the upper and lower nullide plates 3 and 4, and by moving the upper nullide plate 3 or the lower slide plate 4, the small holes 9 are formed in each of them. through the upper part 10a and the middle part 1
0b or middle portion 10b and lower portion 10c can be communicated.

Further, a pair of opposing grooves are vertically formed in the central portion of the opposing inner wall of the cylinder 2 in the upper portion 10a to a depth of approximately the upper nullide plate 3, and the separator plate 1 is inserted into the groove on both sides thereof. It can be inserted and fixed in place.

The separator 11 allows the first and second melts 12a and 12b to be accommodated in the upper portion 10a without mixing with each other.

Further, a plurality of pairs of opposing grooves are formed in the vertical direction on the opposing inner walls of the cylinder body 2 in the upper portion 10a and the middle portion 10b up to the depth of the lower nullide plate 4, and the basic holder 13 is inserted into the grooves.
, 13... on both sides, and the holder is inserted into the middle part 1.
Can be fixed to 0b.

The substrates 14 can be fixed to both sides of each substrate holder 130, and a plurality of substrates 14 can be arranged side by side in the middle portion 10b.

During manufacturing, as shown in FIG.
b, and then insert the upper and lower nullide plates 3 and 4 into the cylinder body 2.

At this time, each small hole 9 is placed outside the cylindrical body 2.

Thereafter, a separator plate 11 is disposed on the upper portion 10a, and different first and second
The second melts 12a, 12b are separately housed in the upper portion 10a.

After setting the boat 1 in a reaction tube set at a predetermined temperature and holding it for an appropriate time, the upper Nuride plate 3 is moved and the first melt 1 is poured through the small hole 9 of the Nuride plate.
2a into the middle portion 10b.

Therefore, the first melt and the substrate come into contact with each other, and when the temperature is lowered in this state, the first epitaxial layer grows.

Thereafter, the lower slide plate 4 is moved to discharge the first melt in the middle portion 10b downward through the small hole 9 of the slide plate 4.

When the discharge is completed, the lower Nuride plate 4 is returned to its original position, the upper Nuride plate 3 is further moved, and the second melt 12b is poured into the middle portion 10b through the small hole 9 of the Nuride plate.

Therefore, when the second melt and the substrate come into contact with each other and the temperature is lowered in this state, the second epitaxial layer grows on the already formed first epitaxial layer.

Through the above steps, the first epitaxial layer of the furnace 2 is continuously grown on the substrate 14.

When making a Gap green light emitting diode, for example, the first melt 12a is a Ga liquid containing GaP*Ga2S3 and GaN, and the second melt 12b is a Ga liquid containing GaP*Ga2S3 and GaN.
When performing the second epitaxial growth using a Ga solution containing N, the zinc set upstream of the reaction tube is sent by steam and zinc is added.

Thus, according to the present invention, two epitaxial layers can be grown successively without taking the substrate out of the reaction tube midway through, so the crystal is not contaminated and, for example, in the case of a light emitting diode, extremely high luminescence can be achieved. Efficiency can be achieved, and since each substrate is placed side by side, the substrates can be arranged at high density, making mass production possible.

[Brief explanation of the drawing]

FIG. 1 is a side view of a GaP green light emitting diode, and FIG. 2 is a sectional view of a manufacturing apparatus in an embodiment of the present invention. 2... Cylindrical body, 3, 4... Upper and lower nullide plates, 12a
, 12b...19th second melt, 14...substrate.

Claims (1)

[Claims] 1 In the liquid phase epitaxial growth method in which crystal growth is performed by contacting the melt with the substrate, the cylinder is divided into upper, middle and lower parts by two upper and lower perforated slide plates, and the upper part has the first and second parts. The two melts are melted and contained without mixing with each other, and a plurality of substrates are arranged side by side in the middle part, and then the upper nullide plate is moved to allow the first melt to flow through the holes in the nullide plate. The first melt in the middle part is discharged into the lower part through the holes of the nullide plate by moving the lower nullide plate, and then the first melt in the middle part is discharged into the lower part by moving the lower nullide plate. The process of melting the middle part and the lower tray again, and the process of moving the upper nullide plate to flow the molten liquid into the middle part through the hole in the slide plate to perform liquid-phase electric growth again. A liquid phase epitaxial growth method characterized by: