JPS6169119A - Boat for liquid-phase epitaxial growth - Google Patents

Abstract

PURPOSE:To obtain the epitaxial crystal of good quality having no flaw on the surface of a wafer while the compositional ratio of each layer is being controlled by a method wherein a gap is provided on the outer arris located on the inner wall bottom part of a bath, and the outer circumference of the hollowed part of the crystal retaining part of a slider is chamfered. CONSTITUTION:A gap 101, wherein a solution is not flow in by surface tension, is provided on the outer arris of the inner wall bottom part of a bath 10, and a chamfer 202 is performed on the hollow part which will be turned to the crystal retaining part 201 of a slider 20. A substrate wafer 50 is provided on the crystal retaining part 201, the bath 10 is placed, and it is fitted to a guide 30. Each molding source is charged into the bath 10, and an epitaxial growing process is performed. Carbon grains, formed particles around nuclei having contamination as nuclei and the like are collected by the slide into the groove formed on the outer arris of the inner wall bottom part of the bath in such a manner that they are not moved on the surface of the wafer. As a result, no flaw is generated on the crystal surface, the carrying in of foreign matters is reduced, and the controllability of the composition of each layer can be enhanced remarkably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a sliding liquid phase growth port used particularly for epitaxial growth of compound semiconductors such as semiconductor laser diodes.

[Conventional technology]

Conventionally, a sliding carbon port as shown in FIG. 2 has been used for liquid phase epitaxial growth of semiconductor laser diodes. That is, the liquid phase growth port shown in FIG. bathtub 10
Quafers held in the crystal holder 201 by the slider 20 sliding on the lower side of the crystal holder 201 are carried to the bottom of each solution, and multilayer growth is performed.

[Problem that the invention seeks to solve]

However, in the conventional port, the carbon bathtub 0 and the slider 20 are worn out by sliding, and a gap is created between them.As a result, the gap between the bathtub 10 fitted to the guide 30 and the slider 20 The previous solution is brought in through the growth layer, making it difficult to control the composition ratio at the growth layer interface and within the growth layer.

As a countermeasure for this, the gap itself can be reduced by using a hard material with less wear and improving machining accuracy, or by attaching a screw 4o to the outer surface of the guide 30 between the bathtub 10 and the slider 2o to reduce the gap. Measures have been taken to suppress this. .

However, if the material used is carbon, it is impossible to completely suppress wear, so screws of 40 mm are used to prevent gaps.
Increasing the tightening force will conversely increase the size of the hole.

Further, carbon powder and particles due to wear adhere to the wafer surface and the growth solution, damaging the wafer surface during sliding, and causing surface contamination problems associated with measures to prevent gaps.

An object of the present invention is to provide a liquid phase growth port that can control the composition ratio of each epitaxial growth layer and obtain a high-quality epitaxial crystal without scratches on the wafer surface.

[Means for solving problems]

The present invention provides a gap, preferably a gap, in which the solution does not flow into the bottom of the inner wall of the bathtub due to surface tension.
/J"m), and preferably the outer periphery of the cutout () of the crystal holding part of the slider is
It is characterized by being chamfered at 0.5 [mm-m].

[Effect]

By using the above-mentioned port, it is possible to reduce the breakage of the corners during sliding, and furthermore, the groove formed on the outer edge of the bottom of the inner wall of the bathtub allows the solute nuclei formed with the carbon particles and dirt to slide. Since the crystal is swept over the wafer surface without being transferred, there are no scratches on the crystal surface and less carry-over.As a result, high-quality liquid phase epitaxial results with extremely high controllability of the composition of each layer. is obtained and productivity is improved.

〔Example〕

The present invention will be described below with reference to the drawings.

Figure 2 shows an embodiment of the present invention, and in particular,
Bl is a partial perspective cross-sectional view of the bathtub 10 and the slider 20, and in the same figure (q is a partial cross-sectional view in which the bathtub 0 and the slider 20 are superimposed. In other words, the bathtub 10 is
A gap 101 is provided at the outer edge of the bottom of the inner wall, in which the solution does not flow due to surface tension. This gap 101 has a height of 30 to L50 [μ@m] and a width of 100 to 500 [μ
・m] is preferable. Further, the grooved portion that becomes the crystal holding portion 201 of the slider 20 preferably has R=0.05 to
The chamfer 202 of O, S [mm] is the finishing.

The substrate wafer 50 is placed on the crystal holding portion 201 of the slider 20 having such a configuration, and the bathtub LO is placed thereon and fitted into the guide 30 as shown in FIG. At that time, as shown in Figure 2, there is no gap between the guide 30, the bathtub 10, and the slider 20, and the slider 2
Finely adjust the screw 40 so as not to prevent it from sliding.

Thereafter, the bath 10 is charged with each growth source, and normal epitaxial growth is performed. According to the implementation results of the present invention, the amount of solution brought in during sliding is extremely small, and high-quality epitaxial crystals with almost no surface scratches can be obtained while ensuring reproducibility of the amount brought in for each growth cycle. Ta. That is, the composition ratio of each epitaxial growth layer is A
t) (Oal-xIn the case of As, the At mixed crystal ratio In the case of AtGaAs, the n-type carrier concentration due to TeK (-as an example, 5±0. It was obtained with good reproducibility and the surface condition was also very good.

Therefore, the number of steps needed to establish various growth conditions associated with port replacement and the number of steps required for preparation therefor are reduced, the reliability of the port is increased, and the productivity of liquid phase epitaxial growth is greatly improved.

Note that the present invention can be applied to various slide type liquid phase epitaxial growth boards depending on the materials used, the substrates used, and the bath size.

[Effects of the Invention] As described above, according to the liquid phase growth method according to the present invention,
While the composition ratio of the epitaxial growth layer is well controlled,
A high quality epitaxial growth layer with no scratches on the surface is provided.

[Brief explanation of drawings]

Figure 1 (8) and Figure 1 (8) are partial perspective sectional views of various parts constituting one embodiment of the present invention, respectively (Q is a sectional view in which the structural members of the same figure (At. (B) are fitted), and ! 2 is a perspective view showing a conventional example. 10...Bathtub, 20...Substrate wafer slide plate (slider), 201...Crystal holding section, 30... ... Guide, 40 ... Set screw for fine adjustment, [0 [ ... Gap, 202 ...
... Floor plan, 50 ... Semiconductor Quafer 0

Claims (1)

[Claims] In a sliding type liquid phase epitaxial growth port having a bathtub part, a wafer slide plate, and a guide part for storing and holding both, a gap is provided at the outer ridge of the bottom part of the inner wall of the bathtub part, and the wafer slide A port for liquid phase epitaxial growth characterized by chamfering the outer periphery of the hollowed out part of the crystal holding part of the plate.