JP2547188Y2 - PCB holder - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate holder for holding a substrate for crystal growth in a liquid phase epitaxial growth method, and more particularly to a substrate holder for preventing a solid material from colliding with the substrate. It is about improvement.

[0002]

2. Description of the Related Art In recent years, techniques for utilizing infrared rays have been rapidly advancing.

As a material for the infrared detecting element, mercury / cadmium / tellurium (H) having a narrow energy band gap is used.
A ternary compound semiconductor crystal made of g _1-x Cd _x Te) has received the most attention because of its high sensitivity and high speed. An image sensor for obtaining infrared rays emitted from an object as an image is made by arranging a large number of minute infrared detecting elements (pixels) two-dimensionally on a plane by photolithography. Since all these pixels need to have the same characteristics with respect to infrared rays, conventionally, the above-mentioned ternary compound semiconductor crystal having uniform characteristics, a large area and a smooth crystal surface has been manufactured for this pixel. In addition, it is required to be divided into small portions.

As a method for obtaining such a large-area compound semiconductor crystal thin film, a liquid phase epitaxial growth method is generally used. This is because the apparatus required for this method is relatively simple, and the composition of the obtained crystal thin film can be easily controlled. However, while having such advantages, for example, there is a difficulty in uniformity of the thickness and composition of the obtained crystal thin film in the film, and a portion that can be used to obtain an element having uniform characteristics. It is pointed out that there is a problem in increasing the production efficiency due to the limited production.

Under such technical background, an improved dipping method which has solved the above-mentioned drawbacks has recently been proposed.

That is, this method encloses a substrate b and a raw material c in an ampoule a as shown in FIG.
While heating this ampoule a in an electric furnace not shown,
After the raw material c is melted to obtain a raw material melt c ′, the ampoule a is rotated 180 degrees together with the electric furnace so that the ampoule a is turned upside down as shown in FIG. The substrate b is brought into contact with the raw material melt c ′ while keeping the surface horizontal. Then, after the raw material melt c ′ is subjected to liquid phase epitaxial growth, the ampoule a is turned upside down again to separate the raw material melt c ′ from the substrate b.

As shown in FIG. 8, the substrate a is formed in a recess d 'which is formed in the substrate holder d, has the same depth as the thickness of the substrate a, has the same shape as the substrate a, and has substantially the same size. The ampoule a is usually adjusted so that the area of the substrate b is about half of the cross-sectional area of the ampoule a.

[0008]

When the improved dipping method is applied, most of the raw material c charged into the ampoule a is a lump or a solidified alloy material.

For example, when the raw material c is melted and epitaxially grown in the ampoule a, since the raw material is of a high purity, most of the raw material form is a lump, and the above-mentioned mercury, cadmium, and tellurium are used. Also in the example of the compound semiconductor crystal made of, except for mercury, the raw material form is massive.

When an alloy for crystal growth is once prepared by melting the raw material in the ampoule a and epitaxially growing the alloy, it is necessary to place a substrate b in the ampoule a in advance to prepare the alloy in the ampoule a. Is exposed to a high temperature, there is a possibility that the substrate b may be melted. Therefore, in a usual method, the alloy is once synthesized with another ampule, and then the solidified alloy material is charged into the ampule a on which the substrate b is installed.

[0011] As described above, the raw material charged into the ampoule a was mostly a lump or a solidified alloy material.

On the other hand, in the ampoule a, the substrate b
8A is held and fixed by the substrate holder d as shown in FIG. 8A, but is not fixed with respect to the solid or solidified solid material c, so that it can freely and easily move in the ampoule a. It is in a state where it can be done.

When the above-mentioned improved dipping method is applied to obtain a large-area thin-film crystal, the amount of the solid raw material c to be put into the ampoule a naturally increases, and accordingly, a large amount of solid material c. Since the raw material c easily collides with the substrate b, there has been a problem that the substrate b is damaged by the movement phenomenon of the solid raw material c.

In particular, when the ampoule a is installed or removed, the solid raw material c tends to move because the impact is applied to the ampoule a during transportation.

The present invention has been made in view of such problems, and an object of the present invention is to provide a substrate holder which can prevent collision of a solid raw material with a substrate.

[0016]

That is, the invention according to claim 1 is arranged at an upper side in a sealed tube, holds a substrate in a concave portion thereof, and seals when the sealed tube is turned upside down. Assuming a substrate holder for contacting the raw material melt disposed on the lower side of the tube with the substrate and performing liquid phase epitaxial growth, a holder body having the recess at substantially the center thereof, and a recess forming surface side of the holder body A shield having a size smaller than the holder main body and having a gap between the outer peripheral edge thereof and the sealed tube so as not to hinder the passage of the raw material melt, and the shield and the holder A coupling tool for coupling with the main body,
Further, the distance from the holder body to the shield is set to be larger than the thickness of the raw material melt layer in contact with the substrate.

In the substrate holder according to the first aspect of the present invention, when the substrate holder is located above the raw material in the sealed tube and the raw material is in a solid state, Since the shield constituting a part temporarily fixes the solid raw material or prevents contact with the substrate, there is an advantage that damage to the substrate can be avoided even if an impact is applied to the sealed tube.

In the invention according to the first aspect, it is desirable that the recess provided in the holder main body has the same depth as the thickness of the substrate, has the same shape as the substrate, and is set to be substantially the same size as in the prior art. .

Further, it is necessary that the shield has a gap between the outer peripheral edge and the sealed tube which does not hinder the passage of the raw material melt. This is because when the raw material melt and the substrate are brought into contact with each other by turning the sealed tube upside down, it is difficult to uniformly flow the raw material melt to the substrate side along the inner wall of the sealed tube without the gap. Therefore, the amount of the raw material melt is blocked between the outer peripheral edge of the shield and the inner wall of the sealed tube, and the amount of the raw material melt flowing into the substrate side is reduced, and the composition of the obtained crystal film is different from the desired composition. This is because there is an adverse effect.

On the other hand, the distance from the holder body to the shield needs to be set to be larger than the thickness of the raw material melt layer in contact with the substrate. This is because, if the thickness is set to be smaller than the thickness of the raw material melt layer, the shield is immersed in the raw material melt, and crystal growth also occurs from the lower surface side of the shield and grows on the substrate. This is because not only the amount of crystals to be reduced is reduced but also the composition shift occurs.

The material of the shield is not particularly limited. For example, it is preferable that the shield is made of the same material as quartz, carbon, ceramics or the like as the material of the substrate holder. Further, the size of the holder needs to be set smaller than that of the holder body so that the flow of the raw material melt to the substrate side is not obstructed when the sealed tube is turned upside down.

At this time, an opening may be formed at the center of the shield depending on the material applied to the manufacture of the shield. However, if the opening does not hinder the temporary fixing of the raw material. There is no particular problem.

Next, as for the above-mentioned connecting tool, the structure is optional as long as the shield and the holder main body are connected while satisfying the above relationship. For example, a separate member from the shield is used. Or an integral member having one end connected to the shield.

The substrate held by the substrate holder according to the present invention is appropriately selected depending on the kind of semiconductor crystal required by the liquid phase epitaxial growth method. For example, mercury / cadmium / tellurium (Hg) described in the prior art is used. _In the case of a ternary compound semiconductor crystal composed of _1-x Cd _x Te), a cadmium tellurium or a compound semiconductor crystal substrate in which at least one of zinc, manganese, and selenium is added to cadmium tellurium is mentioned.

[0025]

According to the first aspect of the present invention, a holder main body having a concave portion at a substantially central portion, and provided on the side of the concave portion forming surface of the holder body away from the holder main body, the size of the holder main body is smaller than that of the holder main body. A shield having a gap between the outer peripheral edge and the sealed tube that does not hinder the passage of the raw material melt, and a connecting tool for connecting the shield and the holder main body, constitute a substrate holder, and The distance from the holder body to the shield is set to be larger than the thickness of the raw material melt layer that comes into contact with the substrate.

When the substrate holder is located above the raw material in the sealed tube and the raw material is in a solid state, the shield constituting a part of the substrate holder temporarily fixes the solid raw material. In order to prevent contact with the substrate, damage to the substrate can be avoided even if an impact is applied to the sealed tube.

On the other hand, when the sealed tube is turned upside down and the substrate holder is located below the raw material and the raw material is in a molten state, there is a gap between the outer peripheral edge of the shield and the sealed tube. Since a gap that does not hinder the passage of the raw material melt is formed, the raw material melt can uniformly flow into the substrate side along the inner wall of the sealed tube, and a crystal film having a desired composition can be obtained. Becomes possible.

Further, since the distance from the holder body to the shield is set to be larger than the thickness of the raw material melt layer, the shield is not immersed in the raw material melt and crystals are formed on the bottom side of the shield. There is no fear of growing.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

Embodiment 1 As shown in FIG. 1, a substrate holder 1 according to this embodiment has a ring-shaped shielding plate 2 and a pair of one-sided ends of which are integrally attached to the ring-shaped shielding plate 2. Bolt connector 3
And the main part of the holder body 4 to which the other end of the bolt-shaped connecting member 3 is attached.

First, the ring-shaped shielding plate 2 and a pair of bolt-shaped connecting members 3 are integrally formed by shaving a thick graphite tube, and are formed as shown in FIGS.
As shown in (C), one end side of the bolt-shaped connecting member 3 is mounted at a position symmetrical with respect to the center of the ring of the ring-shaped shielding plate 2.

On the other hand, the holder body 4 is made of a graphite material processed into a columnar shape, like the ring-shaped shielding plate 1 and the like, and a concave portion 41 for holding a substrate is formed substantially at the center thereof. In addition, a pair of through-holes 42 are formed in portions corresponding to the bolt-shaped connector 3 so as to penetrate the other end of the bolt-shaped connector 3, and the other end of the bolt-shaped connector 3 A nut 5 is attached to the tip, and the holder main body 4 and the ring-shaped shielding plate 2 are connected via the bolt-shaped connecting member 3.

In this embodiment, the through hole 42 is used.
And the diameter of the bolt-shaped connecting member 3 are set to be substantially the same,
When the quartz ampoule 6 is turned upside down, the ring-shaped shielding plate 2 is adjusted so as not to drop due to its own weight due to mutual frictional resistance.

The distance h1 from the upper surface of the holder body 4 to the lower surface of the ring-shaped shielding plate 2 is such that the raw material melt generated by melting the raw material is held on the surface of the substrate 7 as shown in FIG. The gap 8 is set to be larger than the thickness h2 of the melt layer at the time, and between the outer peripheral edge of the ring-shaped shielding plate 2 and the inner wall of the quartz ampoule 6 so as not to hinder the passage of the raw material melt. Is provided.

FIG. 2 shows the concave portion 41 of the holder body 4.
FIG. 7 is a perspective view showing a state where the substrate 7 is mounted on the slab.

According to the substrate holder 1 having such a structure, as shown in FIG. 4, the substrate holder 1 is located above the raw material 9 in the quartz ampule 6 and the raw material 9 is in a solid state. At one time, the ring-shaped shielding plate 2 temporarily fixes the solid raw material 9 to prevent contact with the substrate 7,
Even if an impact is applied to the quartz ampule 6, the substrate 7 is not damaged by the impact. Therefore, it is possible to use a larger substrate 7 than before, and it is possible to increase the input amount of the raw material 9.

On the other hand, when the quartz ampoule 6 is turned upside down and the substrate holder 1 is positioned below the raw material 9 and the raw material 9 is in a molten state (see FIG. 3C), the ring-shaped shielding plate A gap 8 is formed between the outer peripheral edge of the quartz ampoule 6 and the inner wall of the quartz ampoule 6 so as not to hinder the passage of the raw material melt. And the distance h1 from the upper surface of the holder body 4 to the lower surface of the ring-shaped shielding plate 2 is set to be larger than the thickness h2 of the raw material melt layer. No crystal growth occurs on the lower surface side of the substrate.

Therefore, by using the substrate holder according to this embodiment, there is an advantage that a crystal film having a large area and a uniform composition can be efficiently manufactured as compared with the conventional case.

Embodiment 2 A substrate holder 1 according to this embodiment is shown in FIGS.
(B) is substantially the same as the substrate holder according to the first embodiment except that the number of the bolt-shaped connecting members 3 is four.

Embodiment 3 A substrate holder 1 according to this embodiment is shown in FIGS.
As shown in (B), it is substantially the same as the substrate holder according to the first embodiment except that a disk-shaped shielding plate 2 ′ having no opening at the center is applied instead of the ring-shaped shielding plate 2. .

Embodiment 4 The substrate holder 1 according to this embodiment is shown in FIGS.
As shown in (B), a disk-shaped shielding plate 2 'having no opening at the center is applied in place of the ring-shaped shielding plate 2, and a bolt-like coupler integrally formed with the shielding plate. The board according to the first embodiment, except that a connecting member constituted by a bolt connecting member 3 ′ and a nut 5 which are separate from the shielding plate is applied instead of the connecting member constituted by the nut 3 and the nut 5. Approximately the same as the holder.

[0042]

According to the invention, when the substrate holder is located above the raw material in the sealed tube and the raw material is in a solid state, the shield temporarily fixes the solid raw material. Alternatively, in order to prevent contact with the substrate and avoid the damage, a substrate larger than the conventional one can be applied, and the amount of raw material input can be increased.

On the other hand, when the sealed tube is turned upside down and the substrate holder is positioned below the raw material and the raw material is in a molten state, there is a gap between the outer peripheral edge of the shield and the sealed tube. Since a gap that does not hinder the passage of the raw material melt is formed, the raw material melt can flow uniformly to the substrate side along the inner wall of the sealed tube, and the distance from the holder body to the shield is reduced. Since the thickness is set to be larger than the thickness of the raw material melt layer, there is no possibility that crystals grow on the bottom surface side of the shield.

Therefore, there is an effect that a crystal film having a large area and a uniform composition can be efficiently manufactured by the improved dipping method.

[Brief description of the drawings]

FIG. 1 is a perspective view of a substrate holder according to a first embodiment.

FIG. 2 is a perspective view of the substrate holder according to the first embodiment on which the substrate is mounted.

FIG. 3A is a horizontal sectional view of the substrate holder according to the first embodiment set in a quartz ampule, and FIG. 3B.
3A is a sectional view taken along the line BB of FIG. 3A, and FIG.
(A) CC sectional view.

FIG. 4 is an explanatory diagram of an operation of the substrate holder according to the first embodiment.

FIG. 5A is a horizontal sectional view of a substrate holder according to a second embodiment set in a quartz ampule, and FIG. 5B.
FIG. 6 is a sectional view taken along the line BB of FIG.

FIG. 6A is a horizontal sectional view of a substrate holder according to a third embodiment set in a quartz ampule, and FIG. 6B.
FIG. 7 is a cross-sectional view taken along the line BB of FIG.

FIG. 7A is a horizontal sectional view of a substrate holder according to a fourth embodiment set in a quartz ampule, and FIG. 7B.
FIG. 8 is a cross-sectional view taken along the line BB of FIG.

8 (A) and 8 (B) are explanatory views of an improved dipping method in a liquid phase epitaxial growth method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate holder 2 Ring-shaped shielding plate 3 Bolt connection tool 4 Holder main body 5 Nut 6 Quartz ampoule 7 Substrate 8 Gap 9 Raw material 41 Depression 42 Through hole

Claims (1)

(57) [Scope of request for utility model registration] 1. A raw material melt disposed on an upper side of a sealed tube, holding a substrate in a concave portion thereof, and disposed on a lower side of the sealed tube when the sealed tube is turned upside down. A holder for a substrate for liquid-phase epitaxial growth by contacting with a substrate, comprising: a holder body having the concave portion substantially at the center thereof; A shield having a gap which is smaller and does not hinder the passage of the raw material melt between the outer peripheral edge and the sealed tube; and a connecting tool for connecting the shield and the holder body, and A substrate holder, wherein the distance from the holder body to the shield is set to be larger than the thickness of the raw material melt layer that comes into contact with the substrate.