JPS63170915A - Liquid phase epitaxial crystal growth apparatus - Google Patents

Abstract

PURPOSE:To realize growth of an uniform epitaxial layer by burying a weight at the lower part of substrate fixing jig and horizontally holding the substrate being set to the substrate fixing jig. CONSTITUTION:A metal having heavy specific gravity, for example, a weight 2 made of lead, solder, etc., is buried at the lower part of a substrate fixing jig 1 consisting of the quartz formed by connecting a pair of cylinders at the part of half-moon shape. Therefore, in case an ample 4 sealing the substrate fixing jig 1 and melt 3 is inserted to the furnace core tube of the liquid phase epitaxial crystal growth apparatus, the substrate 5 can be set horizontally automatically with the effect of weight 2 without troublesome procedures. Therefore, the substrate 5 can be held horizontally in the melt by turning it for 180 deg.. Thereby, growth of uniform epitaxial layer can be realized.

Description

[Detailed Description of the Invention] [Summary] A weight is embedded in the lower part of the substrate fixing jig, and the substrate set in the substrate fixing jig is held horizontally to enable uniform growth of an epitaxial layer. liquid phase epitaxial crystal growth equipment.

[Industrial application field]

The present invention relates to a liquid phase epitaxial crystal growth apparatus, and particularly to an improvement of a substrate fixing jig.

When manufacturing a back-illuminated device, it is required that the thickness of the epitaxial crystal be uniform in order to equalize the internal quantum efficiency between elements.

Furthermore, in order to make the sensitivity uniform between elements, it is required that the composition of the epitaxial layer be uniform.

However, in a liquid phase epitaxial crystal growth apparatus, if the components of the molten melt include metal elements with large differences in specific gravity, if there is a difference in the depth from the liquid surface of the melt, the molten melt Due to the difference in the composition of the epitaxial layer grown on the substrate, the composition of the epitaxial layer is non-uniform.
The thickness also becomes uneven.

Under the above circumstances, there is a need for a liquid phase epitaxial crystal growth apparatus that can grow a uniform epitaxial layer.

[Conventional technology]

In the conventional liquid phase epitaxial crystal growth apparatus, as shown in FIG. 2, a substrate 5 is set on a substrate fixing jig 11, and the substrate fixing jig 11 and the solid melt 3 are inserted into an ampoule 4. The substrate fixing jig 11 and the ampoule 4 are fixed, the ampoule 4 is sealed, and the perpendicularity between the vertical thread 7 and the substrate 5 is measured using a protractor to determine the horizontality of the substrate 5. Settings are being made.

[Problem to be Solved by the Invention 9] The problem with the conventional liquid phase epitaxial crystal growth apparatus described above is that a substrate fixing jig sealed in an ampoule for setting the horizontality of the substrate is not used for liquid phase epitaxial crystal growth. Since the process uses a thread that is made vertical with a weight and a protractor before being inserted into the furnace core tube of the equipment, there is a large error, and the growth of compound semiconductor crystals whose constituent elements are metal elements with large differences in specific gravity. , if the molten melt contains a metal element with a large specific gravity,
If there is a difference in the depth of the melt from the liquid surface, the composition of the molten melt will differ, and the epitaxial layer grown on the substrate will have a non-uniform composition and a non-uniform thickness.

In view of the above-mentioned circumstances, the present invention aims to provide a liquid phase epitaxial crystal growth apparatus equipped with a substrate fixing jig that is simple and easily procurable.

[Means for solving problems]

The above problem can be solved by embedding a weight at the bottom of the board fixing jig.
This problem is solved by the liquid phase epitaxial crystal growth apparatus according to the present invention, which horizontally holds the substrate set on the substrate fixing jig.

[Effect]

That is, in the present invention, since the weight is embedded in the lower part of the substrate fixing jig, there is no trouble when inserting the substrate fixing jig and the ampoule containing the melt into the furnace core tube of the liquid phase epitaxial crystal growth apparatus. Since the horizontal setting of the board is automatically performed by the action of a weight without performing measurements,
By inverting, the substrate can be held correctly horizontally in the molten melt, allowing for uniform epitaxial layer growth.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

As shown in Figure 1 (al), a weight 2 made of a metal with a large specific gravity, such as lead, copper, solder, etc., is attached at the bottom of a board fixing jig 1 made of quartz, which is made up of two cylinders connected by a half-moon-shaped part. is embedded, and the substrate 5 is set above the center between the cylindrical portions with the growth surface of the epitaxial layer facing upward, as shown in the figure.

When the substrate fixing jig 1 and the melt 3 are inserted into the ampoule 4, the substrate fixing jig 1 and the ampoule 4 are fixed, and the substrate fixing jig 1 and the ampoule 4 are inserted into a furnace core tube of a liquid phase epitaxial crystal growth apparatus (not shown). This action stabilizes the substrate 5 in a horizontally held state.

When the melt 3 is heated and melted to become a liquid, the liquid level becomes horizontal and the ampoule 4 is turned 18 by a reversing mechanism (not shown).
When inverted by 0°, the substrate 5, which had been set above the center with the growth surface of the epitaxial layer facing up, will now be
Conversely, the substrate 5 is held below the center with the growth surface of the epitaxial layer facing down, resulting in a state as shown in FIG. 1(b), and the substrate 5 is properly immersed in the liquid level of the melt 3.

In this way, the board 5 is automatically set correctly and horizontally due to the action of the weight 2 embedded in the board fixing jig 1.
When the ampoule 4 is turned over by 180 degrees, the epitaxial layer growth surface of the substrate 5 is properly immersed in the naturally horizontal melt surface of the melt 3, making it possible to grow an epitaxial layer with a uniform composition and thickness.

〔Effect of the invention〕

As explained above, according to the present invention, the substrate can be set horizontally by using a substrate fixing jig with an extremely simple structure. It has the advantage of being able to be held horizontally and growing a uniform epitaxial layer, and can be expected to significantly improve reliability, making it extremely useful industrially.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing an embodiment of the present invention, and FIG. 2 is a side sectional view showing a conventional substrate fixing jig. In the figure, l is a substrate fixing jig, 2 is a weight, 3 is a melt, 4 is an ampoule, 5 is a substrate, A-A sectional view B-B sectional view (a) lbl before insertion into the furnace core tube Side cross section 2 showing an embodiment of the present invention during growth FIG.

Claims (1)

[Claims] A liquid phase epitaxial crystal growth apparatus characterized in that a weight (2) is embedded in the lower part of the substrate fixing jig (1) to horizontally hold the substrate (5) set in the substrate fixing jig (1).