JPS5976433A - Liquid phase epitaxial growth apparatus - Google Patents

Abstract

PURPOSE:To form a double-layer of crystals in different composition by the liquid phase epitaxial growth method on a substrate by holding a substrate with a pair of members which is internally in contact with a heat resistant sealed tube and by providing a separator as specified being in contact with the holding member and internal wall of tube and a receiving trays formed in disk-shape in both sides thereof. CONSTITUTION:A CdTe substrate 12 is held by the grooves 13 of a pair of quartz bars 14A, 14B which are internally in contact with the quartz tube 11. Two quartz trays 16, 17 are formed in both sides of the longer side of the rectangular quartz separator 15 of which longer sides are internally in contact with the internal wall of tube 11 while the shorter sides are in contact with a pair of quartz bar 14 and these trays are separated from the internal wall through the specified interval. Hg and Cd, Te are respectively measured for the specified values and are placed on the trays 16, 17. In this case, type conductivity and composition x are different. The sealed tube 11 is heated and the fused material of epitaxial layer forming materials 18, 19 can be obtained. Thereafter, the sealed tube is rotated for 180 deg. and HgxCd1-xTe crystal layer in different value of (x) can be laminated on the GaAs substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to an improvement in a liquid phase epitaxial growth apparatus having a closed structure and using a tilting method.

(b) Background of the technology Compound semiconductor crystal 1 containing mercury (Hg) For example, mercury/cadmium/tellurium (Hg1-x Cdx Te) or lead (
Compound semiconductor crystals 1 containing Pb), such as lead-tin-tellurium (Ptg-x 5nXTe), have a narrow energy gap and are therefore used as materials for forming infrared sensing elements.

Such HgI-x caxTe crystals and Pbl-
X8n.

In order to obtain Te crystals in a large area and in a thin layer that is convenient for device formation, a cadmium tellurium ('0dTe) substrate is usually used and HgI-x is deposited on the substrate.
A crystal layer of CdlTe or lead-tellurium (PbTe)
), and a crystal layer of PbI-xSnXTe is formed thereon using a liquid phase epitaxial growth method.

(C) Prior art and problems Conventionally, such liquid-phase evixaxial growth has consisted of a support made of rectangular parallelepiped carbon and a slide member that slides on the support.

For example, a substrate of OeL Te is buried in a recess provided in the support base, and a material of Hg1-xCdxTO is filled in a liquid reservoir in the form of a through hole provided in the slide member. Then, the support stand and the slide member were introduced into a reaction tube in a hydrogen (H2) gas atmosphere, and the reaction tube was heated to produce Hml-xOdXTe.
After melting the material, the slide member is slid onto the support stand, the liquid reservoir of the slide member is placed on the substrate, and the temperature of the heating furnace is lowered to form a crystal layer of Hg1-E0ctxTθ on the substrate. A sliding method is used.

However, with this method, easily evaporable Hg evaporates from the liquid reservoir into the reaction tube before forming a crystal layer15.
There are drawbacks.

Therefore, the present inventors previously proposed a liquid phase epitaxial growth apparatus having a closed structure and using a tilting method as shown in FIG.

Figure 1 is a perspective view of a conventional liquid phase epitaxial growth apparatus.
2 is a sectional view taken along line A-Al in FIG. 1, and FIG. 3 is a sectional view taken along line BB' in FIG. 1.

As shown in FIGS. 1, 2, and 3, the conventional liquid phase epitaxial growth apparatus uses a heat-resistant sealed tube made of quartz or the like.
, C! d. It is composed of a support member 4 made of quartz that is inscribed in the inner wall surfaces of a pair of sealed tubes 1 having recesses 3 on opposing surfaces so as to sandwich and hold a Te substrate 2 therebetween.

Further, a substrate 2 is disposed between the pair of support members 4 in the sealed tube 1.
The material 5 of l(gl, CdxTe to be formed on top) is filled.

Introducing the thus sealed tube 1 into a reaction tube in a heating furnace,
The inverse E-tube is heated and filled with kl-xC (IXT
After melting the material e, the sealed tube 1 is rotated 180 degrees in the direction of arrow C. The two substrates to be processed are immersed in a solution of molten Hg1-xCdTθ, and in this state, the temperature of the heating furnace is lowered, and by lowering the temperature of the solution, Hg is deposited on the substrates.
; A crystal layer of 4-xCdXTe begins to precipitate.

However, in such conventional liquid phase epitaxial growth equipment, only one crystal layer of the same composition can be formed on the substrate.When forming a P-N junction, etc., the conductivity type and composition can be When it is necessary to epitaxially grow different crystal layers into a multilayer structure, the disadvantage is that it is not possible to epitaxially grow such a multilayer structure using conventional equipment.

(d.) Purpose of the Invention The present invention eliminates the above-mentioned drawbacks, and makes it possible to epitaxially grow crystal layers with different compositions on one substrate into a multilayer structure even in the liquid phase epitaxial growth apparatus using the tilting method with the closed structure described above. The object of the present invention is to provide a novel liquid phase epitaxial growth apparatus.

(e) Structure of the Invention To achieve the above object, the liquid phase epitaxial growth apparatus of the present invention includes a pair of support members that are inscribed in a heat-resistant sealed tube and hold the substrate between them, and Each of the pair of short sides is held in contact with the end surface of the support member.

It further comprises a rectangular plate-shaped partition plate such that one of the pair of long sides is held in contact with the inner wall of the sealed tube, and a side of the partition plate that does not contact the inner wall of the sealed tube. From the long side, a pair of arcuate supports on both sides with the long side as a boundary separate the plate from the inner wall of the sealed tube at a predetermined distance, and both ends S in the longitudinal direction of the plate It is characterized in that it is provided so as to be in contact with the end surface of the support member.

(f) Embodiment of the Invention An embodiment of the invention will be described below in detail with reference to the drawings.

FIG. 4 is a perspective view showing an embodiment of the liquid phase epitaxial growth apparatus of the present invention, FIG. 5 is a sectional view taken along line DD' in FIG. 4, and FIGS. Parts up to f) are cross-sectional views showing the operating state of the epitaxial growth apparatus.

As shown in FIGS. 4 and 5, the liquid phase epitaxial growth apparatus of the present invention is provided in a sealed tube 11 made of heat-resistant quartz and has a recess 4 in which a substrate 12 of, for example, CdTo is to be held. A pair of quartz rod support members 14A having 13i
, 14B and one long side is inscribed in the inner wall of the sealed tube 11,
A partition plate 15 is made of a rectangular quartz plate, and the two opposing short sides are in contact with the end faces of the quartz rods 14A and 14B.

A receiver made of two layers of quartz that branches from the long side of the partition plate 15 and is bent into an arc shape with a predetermined gap between them without contacting the inner wall of the sealed tube is composed of plates 16 and 17. ing.

Using the liquid phase epitaxial growth apparatus of this example, C! d, different compositions on Te substrates. That is, X
A case where crystal layers of Igl-X (!dXTe with different values) are stacked in a two-layer structure will be described.

The first layer of Hg1. to be formed on the CdTe substrate is placed in the tray 16. Hg of CdxTe crystal layer forming material
, Od, and Te are weighed and filled to predetermined weights.

Next, the second layer of Hg1-x CdxT is placed in the tray 17.

The crystal layer forming material is the first layer forming material and the conductivity type and
Predetermined amounts of Hg, Cd, and Te are weighed and filled so that the values change.

Then C! into the recesses 13 of the support rods 14A and 14B! d
It is installed so that the Te substrate 12 is sandwiched therebetween.

Next, the epitaxial growth apparatus filled with the OeL Te substrate and the crystal layer forming material was inserted into a bottomed quartz tube with one end unsealed, the inside of the quartz tube was evacuated, and the other end was sealed. Then, the epitaxial growth apparatus is placed inside the sealed tube 11.

Next, the sealed tube 11 thus constructed is introduced into a reaction tube, and the reaction tube is heated in a heating furnace so that the receiving plates 16 and 01? The paulownia material filled therein for forming an epitaxial layer is melted.

This state is shown in FIG.
The first layer of Hgl x cdx Te crystal layer forming material 18 to be formed on the substrate 12 is in the receiving tray 17.
A crystal layer forming material 19 of HEI-xO (1xT6), which is a second resin to be formed on top, is present in a molten state.

Next, such an epitaxial growth apparatus is rotated 180° in the direction of arrow E. Then, the receiver is the molten material N18 in the pan.
．． 19 accumulates at the bottom of the sealed tube, and the substrate 12 comes to be at the top. This state is shown in FIG. 6(b).

Next, such an epitaxial growth apparatus is rotated 180° in the direction of arrow F. Then, the first layer of epitaxial layer forming material 18 comes to accumulate at the bottom of the sealed tube through the gap L1 between the plate 16 and the sealed tube 11, and by rotating the sealed tube in this way, as shown in FIG. As shown in (C), the first layer of HEI, Cd, is melted by the substrate 12 that has entered the bottom of the sealed tube.
It becomes immersed in the x'Te crystal layer forming material. In this state, the temperature of the heating furnace is lowered and the first layer is placed on the substrate.
A crystalline layer of Hg1-xCdXTe is formed. In this case, since the crystal layer forming material PI of the second layer 1 (gl-XaaXTe) is present on the surface 17, the material PI of the first layer Hg1xCdXTe does not mix with each other.

Next, the sealed tube 11 is rotated 180° in the direction of arrow G.

Then, the first crystal layer forming material 18 enters into the tray 16 through the gap 12 between the m116 and the sealed tube 11, as shown in FIG. 6(d).

Next, the sealed tube 11 in this state is rotated 180 degrees in the direction of arrow H. Then, the second layer of Hg4-xCdXTe crystal layer forming material 19 comes to wrap around the bottom of the sealed tube through the gap 3 between the plate 17 and the sealed tube 11, as shown in FIG. 6(e).
As shown in FIG. 1, the base 1y12 is immersed inside the crystal layer forming material 19. At this time, the first layer of crystal layer forming material 18 accumulates inside the tray 16 and does not mix with the first layer of crystal layer forming material 19. In this state, lower the temperature of the heating furnace and
2nd layer of Hg on top; 1. Form a crystalline layer of CdXTe.

Next, the sealed tube 1] in this state is rotated 180 degrees in the direction of the arrow.

In this way, as shown in FIG. 6(f), the crystal layer forming material 19 of the second island enters the receiver ff1117 through the gap 4 between the tray 17 and the sealed tube 11 and accumulates at the bottom of the sealed tube. become. Therefore, the substrate 12 and the melted crystal layer forming material are separated, and a second layer of Hgl'' is formed on the substrate 12.
A crystal layer of CdX'I'e will be formed.

(b)) Effects of the Invention As mentioned above, the liquid phase heating element composition of the present invention has the following effects: Hg, CD, Selenium (Se)
Even when forming an epitaxial layer in a multilayer structure using a material with high vapor pressure such as sulfur (S), the material will not evaporate and scatter during epixaxial growth, and the multilayer structure will not be reproduced. It has the advantage of being able to form a highly sensitive layer.

Further, in the above embodiments, a quartz rod was used as a support rod for holding the substrate with clamps, but there would be no difference even if a support rod made of carbon was used instead of the quartz rod.

[Brief explanation of drawings]

From Figure 1, Figure 1 is a perspective view and a cross-sectional view of a conventional liquid phase J-hytaxial growth device, and Figure 4 is a diagram of a conventional liquid phase J-hytaxial growth device.
FIG. 5 is a perspective view showing an embodiment of a liquid phase epitaxy apparatus, and FIG. 5 is a sectional view taken along line DD' in FIG. 6(a) to 6(f+) are cross-sectional views showing the operating state of the liquid phase eviaxial growth apparatus of the present invention. In the figure, 1.11 is a sealed tube, 2.12 is a Cd Te
313 is a recess, and 4, 14A, and 14B are supporting members. 5 is -Hgl, CdXTe, 15 is a dividing plate, 16° 17 is a plate, 18 is Hgl -x of the first layer
The Cd4Te layer forming material 219 is the second layer of HgI-x
CdxTe layer forming material, C, E, F, G, H, arrows indicating rotation direction + 'I + '2, i3 + '
There is a gap between the 4-piece sealed tube upper support and the plate. Figure 1 Figure 3 Figure 4 Figure 6 Leap (Q) Figure 6 (b)

Claims (1)

[Claims] a pair of support members inscribed in a heat-resistant sealed tube to sandwich and hold the substrate; a pair of short sides shorter than the inner diameter of the sealed tube each in contact with an end surface of the support member; a rectangular plate-shaped partition plate whose long sides are held in contact with the inner wall of the sealed tube; From the side, a pair of arcuate supports on both sides with the long side as a boundary separate the plate from the inner wall of the sealed tube at a predetermined distance,
A liquid phase eviaxial growth apparatus characterized in that both longitudinal ends of the pedestal are provided so as to be in contact with the end surfaces of the pair of supporting members.