JPS6169120A - Boat for liquid growing - Google Patents

Abstract

PURPOSE:To improve the productivity while maintaining the controllability of composition ratio and making a wafer end chamferring needless by a method wherein the outer edges are cut off rectangularly in the sliding direction of crystal holder of a slider. CONSTITUTION:The outer edges of crystal wafer holder 201 of a slider 20 are cut off to place a substrate wafer 60 without chamferring the ends thereof. A bath tub 10 to be charged with each growing source to grow the first window layer 40 of light emitting diode. At the ends of substrate wafer 60, solute is separated at end sides to reduce the thickness of ends in the thickness direction of growing layer. Through these procedures, the distance between the upper surface of slider 20 and the surface of crystal may be reduced so that any charged solution 50 may be cleaned up by washmelt to locate the substrate wafer 60 on the specified position in the second growing solution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sliding liquid phase growth boat used for epitaxial growth of compound semiconductors such as light emitting diodes for communications.

[Conventional technology]

Conventionally, a sliding carbon board as shown in FIG. 3 has been used for liquid phase growth of communication light emitting diodes. That is, the apparatus shown in FIG. 3 is composed of a bathtub section 10, a Quaha slide plate 20 (hereinafter referred to as a slider), and a guide 30, and the bathtub 1° inserted into the guide 30.
The lower side of the 9 wafer is held by the wafer holding portion 20LK by the slide of the slider 20, and the 9 wafer is carried to the bottom of each solution to perform multilayer growth. Generally, the crystal for growth is placed on the crystal holding part 201 of the slider 20, but as shown in the second position, the window layer 40 of the surface-emitting communication light emitting diode has a thickness of 30 to 70 μm. ] Adashi,
LK of several thicknesses of the substrate crystal wafer 60 and the jig layer 401 formed at the edge of the wafer 60 are as follows:
The thickness ranges from several times to 10 times the thickness of the grown layer. Therefore, increase the distance (gap) between the top surface of the slider 20 and the crystal surface! If you do not do this, sliding can be prevented due to solute nuclei, degrowth, and degrowth. However, if the gap is made too large, each solution will be brought in through the gap, and the controllability and reproducibility of the composition ratio and carrier concentration of the growth interface and the subsequent growth layer will deteriorate.

For cleaning solution (
Although it is possible to control the composition ratio to some extent by using wash melt), according to the study of the present inventor,
It is clear that the reproducibility of the wash melt effect is poor at a gap of about 300 [μ·m3 or more], so the gap must be suppressed to 50 to 200 [μ·m]. For the above reasons, when epitaxially growing light emitting diodes for communication, the edges of the IC wafers are chamfered in advance for practical use.

[Problem that the invention seeks to solve]

However, chamfering the edges of the wafer has a high risk of introducing defects to the wafer surface during the process, which poses a problem in terms of device reliability, and requires additional work such as cleaning processes. , during liquid phase epitaxy 1. 2□. ,,Ayo7
．． Yoko,.

The purpose of the present invention is to maintain controllability of the composition ratio of each growth layer,
It is an object of the present invention to provide a boat for liquid phase growth that can improve productivity by eliminating the need for chamfering of wafer edges.

[Means for solving problems]

In the present invention, the outer edge of the crystal holding portion of the slider in the direction perpendicular to the sliding direction preferably has a width of 0.2 to 2.0 (mm).
It is characterized in that it is scraped off so that the growth solution also comes into contact with the side surface of the end of the wafer.

[Effect]

By using the boat described above, solute precipitation also occurs on the side surfaces of the ends, and the thickness of the grown layer at the ends in the thickness direction can be reduced. For this reason, it is possible to further reduce the gap, and the controllability of the composition ratio of each layer is further improved.Furthermore, it is possible to use a substrate wafer without chamfering the edges, so it is possible to improve the controllability of the composition ratio of each layer. The reliability of the process has been improved, the number of processing steps has been reduced, and the productivity of epitaxial growth has been improved.

〔Example〕

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

Figure 2 shows an embodiment of the present invention, in which the outer edge of the crystal holding portion 201 of the slider 20 is shaved off. Width 0.2
It is preferable to shave by ~2.0 (mm)K.

Here, a substrate wafer without chamfered edges is installed.1. The gap should be 150Cμm].

Next, as in FIG. 3, the bathtub 10 is placed on the slider 20 and inserted into the guide 30 from one side. After that, charge the bathtub LOK with each growth source and heat it to 850°C.
] and then slowly cooled at 0.2 [C/Min] to form the first window layer 40 of the communication light emitting diode to about 50 [μ
・M] Let it grow. At the end of the substrate wafer placed in the crystal holding section 201, as shown in ) in FIG.
μ・m], and the sides have a thickness of 50 to [OO[μ・m]
grow up. Since the gap is 150 [μ・stone], the sliding of the slider 20 is not prevented, and the amount brought in is washed away with wash melt, and the substrate Quaeno is positioned at the position of the subsequent second layer growth solution. be able to. By epitaxially growing the necessary layers one after another, we can control the composition ratio of each layer with good reproducibility.
Moreover, a high-quality grown crystal of a light-emitting diode for communication was obtained without any process accidents such as slide stoppage due to decrose.

〔Effect of the invention〕

As described above, according to the boat of the present invention, a grown layer can be obtained with good reproducibility without having to take the semiconductor wafer again.

[Brief explanation of drawings]

Figure 2 is a perspective view showing one embodiment of the present invention, and Figure 2 (A
l, (a is a sectional view of shrimp wafers according to a conventional example and an embodiment of the present invention, respectively, and FIG. 3 is an external view showing a conventional example. 10... bathtub, 20...・Substrate wafer slide plate (slider), 30... Guide,
20L...Group/crystal holding part, 40...Wind layer of surface emitting type, communication light emitting diode, 50...
・Growth solution.

Claims (1)

[Claims] In a slide-type liquid phase epitaxial growth boat having a bathtub section, a wafer slide plate, and a guide section for storing and holding both, the outer edge of the crystal holding section provided on the wafer slide plate is scraped off, and the growth solution is applied to the substrate. A boat for liquid phase growth, characterized in that it also comes into contact with the side surface of the end of a wafer.