JPS6136108A - Method of pretreatment of indium metal and its jig - Google Patents

Abstract

PURPOSE:To seal ampul by a simple operation in a short time, and to obtain high-purity In-P polycrystal, by placing In and P in a long cylindrical quartz ampul with a bottom, inserting a specific quartz cap into it, carrying out a reaction under heating in a vacuum. CONSTITUTION:P is placed on the inner bottom part 13a of the long cylindrical quartz ampul 13 with a bottom, and In put in the quartz boat 15 is placed on the middle part 13c, the short cylindrical quartz cap 16 with a bottom provided with the plural dented channels 16 a in the longer direction at equal intervals on the outer peripheral face, having a cross section of regular wavy shape and the maximum diameter part 16b of the shape somewhat smaller than the inner diameter of the ampul 13 is inserted into the middle part between the opening 13b and the boat 15, the ampul is introduced into the baking furnace 11, and supported by the supporting tool 14. The ampul is then evacuated from the vacuum attachment 17, the interior of the ampul 13 is kept at = 10<-5>Torr, the furnance 11 is transferred to a given position, the cap 16 and the boat 15 is heated at 800-900 deg.C, the bottom part 13a at 100-150 deg.C, so that the ampul 13 melted, the inside face of it is pressed to and welded to the cap 16, and the ampul is sealed, to give high-purity In-P polycystal.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention involves baking In and P at a predetermined temperature in a vacuum, and then sealing them in an ampoule while maintaining the vacuum state for synthesis. The present invention relates to a pretreatment method for synthesizing high-purity InP polycrystals and a jig therefor.

BACKGROUND ART Generally, when synthesizing InP high-purity polycrystals, the following pretreatment is performed. That is, as shown in FIG.
1. In is placed in a quartz boat 15 in the middle part 13c of the ampoule 13, and a short cylindrical quartz cap 1 with a bottom is inserted between the ampoule opening 13b and the boat 15. Then, the inside of this ampoule is set to a high vacuum [2] In and P
are baked in a baking furnace 4 to a predetermined temperature to sufficiently volatilize impurities, the vapor pressure of P is kept constant, and after baking, the cap 1 and ampoule 13 are placed in a bath while maintaining the above vacuum level. The ampoule is sealed and used as a raw material for the next InP synthesis process.1 Problems to be Solved by the Invention By the way, in the past, a cap was used as a cap to seal the ampoule 13 after baking was completed, as shown in Figures 3(a) and (b). ) was used, the cap 1 having a smooth cylindrical side wall.

When welding the bottomed long cylindrical quartz ampoule 13 and the bottomed short cylindrical camp 1 inserted therein,
When the ampoule 13 is heated from the outer periphery, the heated part softens and is welded to the outer periphery of the cap 1 due to the internal vacuum.
As shown in Figure 2, wrinkles 2 are formed in some areas, and micropores 3 are formed in the wrinkles 2, and it takes time to completely close the holes, or microscopic pinholes are formed. remains, destroying the inner wall, adsorbing impurities in the atmosphere, and making it unusable for the next process.

Furthermore, as shown in FIG. 2, in the past, since the camp 1 was placed in a quartz ampoule 13 located outside the baking furnace 4, impurities evaporated from the raw material In and In vapor were deposited on the cap, resulting in InP condensation. There was a drawback that high purity InP polycrystals could not be obtained due to the rounding process.

Means for Solving the Problems ゛In view of the above circumstances, the present invention provides a pretreatment method for synthesizing high-purity InP polycrystals that can easily perform controlled baking in a short time, and sealing of ampules after baking. The purpose is to provide a jig that is easy to use and does not cause wall damage to the ampoule, and its gist is that when baking indium metal in a vacuum,
A cylindrical quartz ampoule with a bottom, and a short cylindrical bottom with a diameter that can be inserted into the ampoule, and a quartz camp with a plurality of grooves along the length on the outer circumferential surface. The present invention provides an indium metal pretreatment method and a jig therefor, which uses the quartz camp and the indium metal and maintains the quartz camp and the indium metal at substantially the same temperature. That is, a quartz ampoule in the shape of a long cylinder with a bottom is inserted along the axis into a tubular baking furnace that is movable along the longitudinal axis, and the baking furnace is movably connected to the ampoule. supporting and placing P at the bottom of the ampoule,
A quartz boat containing In is placed in the middle, and a short cylindrical quartz camp with a bottom and a plurality of grooves in the length direction on the outer periphery is inserted between the boat and the ampoule opening. The inside of the ampoule is evacuated to a predetermined degree of vacuum from the ampoule opening, the quartz cap and the indium metal are held at substantially the same temperature, and the In and P are baked at a predetermined temperature. The furnace is moved toward the bottom of the ampoule, and the cap portion is heated to the same extent as the outer periphery of the ampoule, and while the inside of the ampoule is maintained at a predetermined degree of vacuum, the camp and the ampoule are welded and the ampoule is sealed.

FIGS. 2(a), (b), and (c) show high-purity In according to the present invention.
This figure shows an example of an apparatus for carrying out a method for pre-synthesis of P polycrystals and an embodiment of a jig used in this method, and FIG. 1(a) is a longitudinal cross-sectional view of the apparatus. Code 11 in the figure
is a tubular baking oven, and wheels 11& are attached to this baking oven 11.

The wheels 11a are placed on rails 12, and the baking oven 11 is movable along the longitudinal axis. A quartz ampoule 1.3 in the shape of an elongated cylinder with a bottom is inserted into the center hole 11b of the baking furnace 11. The ampoule 13 is supported by a support 14 so as to be movable without being obstructed by the baking oven 11 or the ampoule 13.

P is placed directly on the bottom 13a of this ampoule 13,
In is placed in a quartz boat 15 in the intermediate portion 13e. A quartz cap 16 is inserted between the bow 15 and the opening 13b of the ampoule 13 in the vicinity of the bow 15, and the baking furnace 11 is connected to the ampoule 13.
If the camp 16 and the boat 15 are in the +r00-900°C zone, the bottom 13&gt;

It is configured to have a band of 0°C to 0°C.

Further, a water cooling attachment 17 for evacuating the inside of the ampoule is attached to the ampoule opening 13b.

The quartz cap 16 is a short cylindrical body with a bottom that can be inserted into the ampoule 13, as shown in FIGS. The cross section of the ampule 16 has a smooth regular waveform, and the diameter of the circle circumscribing the tip of the convex portion 16b of this waveform is slightly smaller than the inner diameter of the ampoule 13, and the opening end 16c is connected to the ampoule opening 13b.
It is inserted into the ampoule 13 in the same direction.

Action First, place P1 bow) (In) 15 in the predetermined position of ampoule 16.
, and a cap 16 are placed, inserted into the center hole 11b of the baking oven 11, and supported by one support 14. Next, the baking oven 11 is moved and adjusted so that the temperature range is at a predetermined position with respect to the ampoule 13. Next, vacuum is drawn from the true attachment 17, the inside of the ampoule 13 is held at /0-5'porr K, and baking is performed to remove In and P in the boat.
Impurities attached to the surface are removed by volatilization. In this case, cap 1 makes camp 16 and boat 15 in the same temperature range.
If the temperature of part 6 is low, impurities evaporated from boat 15 and In vapor will be deposited on camp 16, preventing impurities from being mixed into the synthesized InP polycrystal, which will prevent the ampoule from being melt-sealed. This is to prevent this. In addition, since the camp 16 is provided with the groove 16a, the conductance during evacuation is large, and not only can a vacuum be achieved in a short time, but also the adhesion of vapor deposits is suppressed. Furthermore, it is possible to easily bring the cap into close contact with the ampoule during sealing after completion of baking.

Baking the above zone at a predetermined temperature for j-r hours,
Next, the baking furnace 13 is moved, and the cap 16 is moved to the outer circumferential side of the ampoule 13 using a hydrogen flame burner (not shown).
Heat it up. In this case, the inside of ampoule 13 is /0-5'
Since the ampoule 13 is held in the l'orr position, it is easily crushed, and the inner surface of the ampoule 13 shown in FIG. Since the ampoule 13 is pressed against the outer periphery of the camp 16 in a stretched state, the ampoule 13 is welded without creating micropores, and the ampoule 13 is reliably and easily sealed.

In the above description, the cross section of the camp has a regular waveform, but the waveform may be large or small as long as it is a smooth waveform and the tip of the convex portion is close to the inner circumference of the ampoule.

EXAMPLES AND COMPARATIVE EXAMPLES Using the above-mentioned baking furnace, it is possible to easily carry out the prescribed baking process, and when sealing ampules, welding can be carried out smoothly. The advantages and disadvantages of the jig using a short cylindrical camp with a bottom are compared based on the carrier concentration of the synthetic ingot.

The pretreatment conditions were vacuum degree 2, 0-5'porr, I
n baking temperature: ♂10℃, P baking temperature: io
o°C, In of purity 6-N: 200f, P of purity +-N
Experiments were conducted using f+ 'θV to measure the physical properties of 1, P synthesized with In and P under certain synthesis conditions. The results are shown in Table 2.

As is clear from Table 2, it can be seen that when the jig according to the present invention is used, a low carrier concentration can be achieved even in a short baking process. First, if the quartz cap part is kept at a low temperature, the purity will not increase even if it is baked for a long time.

As described above, it can be seen that the 9 jigs using the caps provided with the grooves are significantly superior.

Effects of the present invention As described above, the method and jig according to the present invention are movable relative to the baking oven or the ampoule, so they are easy to operate. , the ampoule can be reliably sealed in a short time, and the high-purity InP polycrystal can be kept in a high vacuum at all times, so there is no generation of oxides or nitrides, and the synthesis pretreatment method and its It is an excellent jig.

[Brief explanation of drawings]

2(a), 2(b), and 2(c) show an example of the apparatus used in the method of the present invention and an embodiment of the jig used therein. Front view, Figure 2 (
b) is a perspective view of the optical cap inserted into the ampoule, Figure 2 (
C) is a view taken along the line I-1 in FIG. 2(b), FIG. 2 is a vertical sectional view of the conventional device, and FIGS. 3(a), (b), and 3 are views of the conventional jig. Fig. 3(a) is a perspective view of the cap inserted into the ampoule, and Fig. 3(b) is a perspective view of the ampule shown in Fig. 3(a).
-■ Linear view and reference figure are front views of the camp and ampoule welded together. 11...Tubular baking oven, 11a...
・Wheel, 11b... Center hole, 13...
Bottomed cylindrical quartz ampoule (ampule), 13a...
...Bottom: tab...opening, 13C...
...Middle part, 14...Support, 15...
...Quartz boat, 16...Quartz cap with longitudinal grooves on the outer circumferential surface, 16a...Concave grooves,
16b... Convex portion, 16C... Open end.

Claims (2)

[Claims] (1) When indium metal is heated and baked in a vacuum, a quartz ampoule with a long cylindrical shape with a bottom and a short cylindrical shape with a bottom with a diameter that can be inserted inscribed in the ampoule are used. 1. A method for pretreatment of indium metal, comprising using a quartz cap provided with a plurality of grooves along its length, and maintaining the quartz cap and indium metal at substantially the same temperature. (2) A long cylindrical quartz ampoule with a bottom, and a short cylindrical body with a bottom having a diameter that can be inserted into the ampoule, with a plurality of concave grooves along the length direction on the outer peripheral surface. A jig for pre-treatment of indium metal, consisting of a quartz cap.