JPS63114A - Liquid phase epitaxy - Google Patents

Abstract

PURPOSE:To contrive to easily make uniform the composition and thickness of grown layers by arranging solution tanks of first and second solution reservoirs in a manner that each tank enters into another solution reservoir alternately so the growing solutions filling the solution reservoir communicate with each other. CONSTITUTION:This device is composed of a substrate holder 4 in which an InP substrate 1 is attached to a containing recess, a solution holder 5 provided with InP growing solution reservoirs 9 and InGaAsP growing solution reservoirs 10 which are separated from one anther, and a boat 6 for mounting the substrate holder 4 and the solution holder 5. The InP growing solution reservoir 9 and the InGaAsP growing solution reservoir 10 comprise plural solution tanks 9a-9d and 10a-10d respectively and the solution tanks 9a-9d and 10a-10d extend under a central partition 5a of the solution holder 5 and penetrate through the adjacent growing solution reservoirs 10 and 9. Because a capacity of the growing solution reservoirs 9 and 10 is large, the change of composition due to the exhaustion of a solute becomes small. Accordingly, the modulation of the growing conditions is not neccessary when forming multiple growth layers and the composition and thickness of the layers become uniform.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a liquid phase growth method used in the manufacture of semiconductors, and more specifically, a liquid phase growth method for repeatedly growing different types of semiconductor layers in multiple layers. The present invention relates to an epitaxial growth method.

(Prior art) Conventionally, in order to repeatedly grow a large number of different types of semiconductor layers, such as a black reflective film using multiple quantum well layers or multiple semiconductor layers, it has been necessary to make the composition, thickness, etc. of each layer uniform. to 1
Molecular beam epitaxy, organometallic vapor phase epitaxy, etc. have been mainly used.

However, as is currently well known, the liquid phase growth method is the best in terms of the simplicity of the growth equipment, price, crystallinity of the growth tank, etc., so it is recommended to form a multilayer growth tank using the liquid phase growth method, which has good controllability. This is extremely important in practical terms.

A conventional liquid phase growth method for obtaining a multilayer growth reservoir will be explained with reference to FIGS. 4 to 6.

In addition, in order to simplify and make the explanation more concrete, I shown in FIG.
An InGaAsP layer 2 and an InP layer are formed on the surface of the nP substrate 1.
A liquid phase growth method for forming a repeated multilayer growth film of layer 3 will be explained.

FIG. 5 is a cross-sectional view of a growth boat used in a conventional liquid phase growth method. It consists of a boat stand 6 on which a holder 4 and a solution holder 5 are placed, and the solution holder 5 is provided with three solution tanks, and the InP growth solution 71 is placed in the solution tanks at both ends.
, 7□ respectively contain an InGaAsP growth solution 8 in the central solution tank.

The growth conditions are such that after being immersed in a solution with a liquid temperature of 620°C in a hydrogen atmosphere for 1 hour, the liquid temperature is lowered to 600°C at a cooling rate of 0.7°C/min to perform growth.

A liquid phase growth method using such a growth boat will be explained. First, pull out the substrate holder 4 to the left, attach the InP substrate 1 to the accommodation recess, and then slide it to the right.
The InP substrate 1 is kept under the solution tank at the left end and brought into contact with the InP growth solution 71 for a growth time t□ to grow the InP layer 2.Next, the substrate holder 4 is slid to the right, and as shown in the figure. As shown, the InP substrate 1 is placed under the central solution tank, and the I
In is brought into contact with the nGaAsP solution 8 for a growth time t2.
Growth of GaAsP layer 3 Next, the substrate holder 4 is continuously slid to the right and brought into contact with the InP solution 7□ at the right end for a growth time t, thereby growing the InP layer 2. The substrate holder 4 is again slid to the left, and the InP substrates 1 are sequentially stopped under the adjacent solution baths, and the growth solutions 8, 7□, 8, 7, .・
By contacting the InGaAsP growth solution 8 and the InP growth solutions 7□ and 72 in this order, the multilayer growth reservoir shown in FIG. 4 can be obtained.

(Problem to be solved by the invention) However, as the growth reservoirs are successively formed, the solute in the growth solution is depleted, and the growth rate changes. t□t ts* t
There was a problem in that it was necessary to adjust i. In addition,
For InGaAsP growth solution.

There was also a problem that compositional fluctuations occurred, and the compositions were significantly different between the first growth reservoir and the last growth reservoir. Therefore, in the case of an InGaAsP layer where the growth conditions are not complicated, there is a problem in that compositional fluctuations are essentially unavoidable.

As a measure to prevent the depletion of solutes in the above growth solution, the fifth
As shown in the figure, solution tanks corresponding to the number of laminated layers are provided in the solution holder 5, and InP solutions 7□, 72...7□ and InGa
AsP solution8. ...81. It is also possible to form a multilayer growth reservoir by accommodating the InP growth solution and InG growth solution alternately and sliding the substrate holder 4 in one direction from left to right.
It is practically impossible to make the composition of the aAsP growth solution uniform, and there is also the problem that the length of the growth boat will become infinitely large if the solution tanks are provided in accordance with the number of stacked layers.

The present invention solves the above-mentioned problems and provides a liquid phase growth method in which the composition and film thickness of each growth reservoir can be made uniform.

(Means for Solving the Problems) In order to solve the above problems, the growth boat of the present invention includes a first solution tank having a plurality of solution tanks forming a first semiconductor growth tank, and a second solution reservoir having a plurality of solution tanks isolated from the first solution reservoir forming a second semiconductor growth reservoir having a composition different from that of the first semiconductor;
Each of the first and second solution reservoirs is arranged so as to alternately fit into the other solution reservoir, and each solution reservoir is filled with the growth solution so as to communicate with each other.

(Function) With this configuration, the first and second semiconductor growth reservoirs are grown, and the growth solutions in the plurality of solution tanks are mixed in the first and second solution reservoirs, so that multilayer growth is possible. It becomes possible to easily equalize the composition and film thickness of each semiconductor in the reservoir.

(Example) An example of the present invention will be described with reference to FIGS. 1, 2, and 4. Although FIG. 4 is used as a specific example to explain the conventional example, this embodiment will also be explained with reference to FIG.

FIG. 1 is a perspective view of a growth boat according to the present invention.

The growth boat includes a substrate holder 4 in which an InP substrate 1 is attached to a recess, and an InP growth solution reservoir 9 isolated from each other.
and a solution holder 5 provided with an InGaAsP growth solution reservoir 10, and a boat stand 6 on which the substrate holder 4 and solution holder 5 described above are placed.

InP growth solution reservoir 9 and InGaAsP growth solution reservoir 1
0 have a plurality of solution tanks 9a, 9b, 9c, respectively.
, 9d and 10a, 10b, 10c, 10d
are provided, and the respective solution tanks 9a to 9d and 10a to 10d are connected to the central partition wall 5a of the solution holder 5.
and extend through adjacent growth reservoirs 10 and 9.

2(a) and 2(b) are views of A-A' and B-B' cut planes passing through the center planes of the InP growth solution reservoir 9 and InGaAsP growth solution reservoir 10 shown in FIG. 1 from the front, respectively. FIG.

The InP growth solution 7 placed in the InP growth solution reservoir 9 shown in FIG. 2(a) is filled in each of the solution tanks 9a, 9b, 9c, and 9d, as well as the solution tanks 9 shown in FIG. 2(b).
a.

9b, 9c and 9d are also filled under the central partition wall 5a. - On the other hand, the InGaAsP growth solution 8 placed in the InGaAsP growth solution reservoir 10 in FIG.
In addition to the solution tank 10a shown in FIG.
, 10b, 10c and 10d are also filled under the central partition wall 5a. The growth solutions in the plurality of solution tanks of each of the growth solution reservoirs 9 and 10 are as follows.

They communicate with each other above the above-mentioned through-hole. Each growth solution reservoir 9
And since the capacity of 10 is large, there is little change in composition due to solute depletion. Therefore, when forming a multilayer growth reservoir, there is no need to adjust the growth conditions, and the composition and thickness of each layer can be made uniform.

Furthermore, since the composition of the growth solution is stable, there is no need to provide solution tanks according to the number of layers in the multilayer growth tank, and the substrate holder 4
can be moved back and forth to sequentially contact the growth solution.

In this example, the semiconductor layers to be laminated are InP and InG.
Although two types of aAsP are used, it is also possible to repeatedly grow three or more types of semiconductor layers. In addition, I
Not limited to the combination of nP and InGaAsP, but also AlGaAs
Of course, combinations of ANGaSb and GaA, ANGaSb and GaSb, and other combinations are also suitable.

FIG. 3 is a schematic perspective view of a second embodiment of the apparatus used in the method of the present invention, in which the same reference numerals as in FIG. 1 indicate the same parts.

In the figure, reference numeral 5b denotes a central partition wall formed in a zigzag pattern, so that mutually opposing portions of the growth solution reservoirs 9 and 10 are inserted into other growth solution reservoirs alternately. The length or width of their mutual penetration is the length or width of the substrate 1
It is determined depending on the width of the layer formed above. In this embodiment, the growth solution in each solution bath communicates with the portion facing the side wall of the solution holder.

(Effects of the Invention) As explained above, according to the present invention, by using a multilayer growth method in which multiple semiconductor layers are repeatedly grown, the composition and film thickness of each growth reservoir can be easily uniformized without requiring complicated adjustments. It is possible to convert

[Brief explanation of drawings]

FIG. 1 is a perspective view of a growth boat used in the liquid phase growth method of the present invention, and FIGS. 2(a) and (b) are cross sections of A-A' and B-B' shown in FIG. 1, respectively. A sectional view, FIG. 3 is a perspective view of another example of a growth boat used in the method of the present invention,
FIG. 4 is a structural diagram of a multilayer growth tank, and FIGS. 5 and 6 are sectional views of a conventional growth boat. 1...InP substrate, 2...InP layer, 3
..., InGaAsP layer, 4... substrate holder, 5... solution holder, 5a... partition, 6
...Boat stand, 7,71,7. ,? ,,,-In
P growth solution, 8*81r 8. - InGaAsP growth solution, 9 - InP growth solution reservoir, 9a, 9b
, 9c, 9d. 10a, 10b, 10c, 10d-solution tank, 10
- InGaAsP growth solution reservoir. Patent applicant Matsushita Electric Industrial Co., Ltd. Figure 1 p' 6-11 Boat 6 9--- inp bottom support eyebrow υ-1nGaAsPA+m? L reservoir Fig. 2 (a) Fig. 3 Fig. 4 Fig. 5

Claims (1)

[Claims] When repeatedly growing multiple semiconductor layers of different types using a growth boat that has a substrate holder for attaching a substrate and a solution holder for storing a solution, and in which the substrate holder and the solution holder are movable relative to each other, the first step is to a first growth solution reservoir provided with a plurality of solution tanks for forming a semiconductor layer, and a second growth solution reservoir for forming a second semiconductor layer having a structure different from that of the first semiconductor layer; A second tank with multiple isolated solution tanks
A growth solution reservoir is provided in the solution holder, and the plurality of both solution tanks are arranged alternately so that the solution tank of one growth solution enters the other growth solution reservoir, and each growth solution is placed in the solution holder. Fill each reservoir so that the plurality of solution tanks are in communication with each other, slide the substrate holder against the solution holder, and place the substrate attached to the substrate holder into the solution tanks of the first and second growth solution reservoirs. A liquid phase growth method, characterized in that first and second semiconductor layers are laminated on the surface of the substrate by sequentially contacting the first and second growth solutions.