JPS6041037B2 - Manufacturing equipment for high dissociation pressure compound single crystal for semiconductors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for producing single crystals of high dissociation pressure compounds for semiconductors such as gallium silicide, gallium phosphide, and indium phthalide.

Accordingly, as an example of manufacturing equipment for a single crystal of a high dissociation pressure compound for semiconductors, as illustrated in the schematic longitudinal cross-sectional view in FIG. For example, a bottle-shaped quartz rotary crucible 2 containing magnetized gallium 8 and supported by a graphite susceptor 10 fixed to the upper end of a rotating shaft 9, and an oxidized sealing crucible that is heated by an after-heater 3 to become a brood liquid. The element 5 is inserted into the crucible 2 leaving behind the quartz cover 4 which is fitted with iron on the upper end of the crucible 2. A rotary pulling shaft 6 with a seed crystal 12 attached thereto is hermetically mounted inside the metal container 1, and after the inside of the metal container 1 is evacuated from the exhaust system 14 to create a vacuum, the inside of the trapping lid 4 is closed. The upper end of the crucible 2 is sealed by heating the boron oxide 5 by the after heater 3 to form a kudzu liquid, and then an inert gas such as argon is introduced from the inert gas introduction system 13 to close the crucible. While creating an inert gas atmosphere outside the crucible 2, the magnetized gallium 8 in the crucible 2 is heated to a melt by the main heater 7, and the rotating pulling shaft 6 and the bottle-shaped crucible 2 are rotated. At the same time, the rotary pulling shaft 6 is lowered so that the seed crystal 12 attached to the tip of the rotating pulling shaft 6 via the chuck 11 comes into contact with the gallium sulfide kudzu liquid 8, and then the rotating shaft 6 is also rotated. An apparatus (hereinafter referred to as a conventional single crystal manufacturing apparatus) has been proposed that grows a single crystal 15 by pulling the single crystal 15 while causing the single crystal to grow. In this conventional single crystal manufacturing apparatus, the grown single crystal 15 is not exposed to an inert gas atmosphere at high temperatures due to the boron oxide liquid seal 5, so that dissociation of the pilasters from the surface of the single crystal 15 is suppressed. This has the advantage that the crystallinity near the single crystal surface is not inhibited, but on the other hand,
[a} Evaporated matter from the surface of the gallium oxide melt 8 adheres to the inner surface of the heated wall of the pin-shaped quartz rotary crucible 2 as gallium oxide, and eventually blocks the view from the outside and prevents the growth during pulling. Not only does this make it impossible to observe the single crystal 15, but small pieces of the adhering gallium phosphide sometimes peel off and fall directly onto the surface of the gallium phosphide melt 8, disturbing the monocrystalline growth conditions and preventing single crystallization. To prevent damage.

'b- In order to minimize the flow of the boron oxide melt 5 for sealing along the rotational pull-up shaft 6, the gap between the rotary pull-up shaft 6 and the quartz lining lid 4 is made as small as possible. Therefore, it is likely that the smooth counter-rotation of the rotating pull-up shaft 6 and the bottle-shaped quartz rotating crucible 2 will be hindered, and the rotating crucible 2 will be vibrated each time. This vibration of the rotating crucible 2 is transferred to the surface of the gallium sulfide melt 8 and adversely affects the quality and yield of the single crystal 15.

{c} The quartz rotating crucible 2 is expensive because it is a bottle-shaped unit with a special shape.
When increasing the size of the crucible, it becomes more expensive, and the larger the crucible, the more easily it deforms due to the pressure difference between the inside and outside of the rotating crucible, and the weight placed on the lower part also increases, causing deformation. If the rotating crucible 2 is deformed, the rotation in the direction of interaction with the rotating pull-up ball 6 will not be carried out smoothly, making it substantially difficult to produce a single crystal. {d} Because the saddle-fitting lid 4 is manufactured from quartz, it breaks after each single crystal growth, and must be replaced with a new one each time, which causes an increase in manufacturing costs. . It had problems such as:

The present invention solves the problems of the conventional single crystal production equipment described above, and provides an equipment for economically producing high dissociation pressure compound single crystals for semiconductors with good crystallinity and mass production, and which can be commercialized widely. It is supported on the upper end of the rotating shaft,
and a high dissociation pressure compound melt (this high dissociation pressure compound melt may be formed by directly melting a polycrystalline material, or it may be formed by a single component such as Ga and AS in the case of gallium sulfide).
and a crucible holding a boron oxide melt for coating this, and a Mo or Mo crucible holding a boron oxide molten liquid for sealing at the upper end. The crucible has a lid made of an alloy and has an outer diameter smaller than the inner diameter of the crucible. A quartz furnace core tube made of aluminum oxide, aluminum nitride, titanium oxide, titanium nitride, aluminum oxide, aluminum nitride, titanium oxide, titanium nitride, titanium carbide, room garnish,
Base, carbide, base, nitride.

The above-mentioned quartz is coated with a protective layer made of a material that is scale-reactive to volatile components in the boron oxide melt and the high dissociation pressure compound melt, such as boron carbide, carbon, Mo, Au, and Pt. A rotating pulling shaft that penetrates the furnace core tube and is attached to be rotatable and pullable, and has a seed crystal attached to its tip, and is fixed to the rotating lifting pot in the quartz furnace core tube. The present invention is characterized by an apparatus for producing a single crystal of a high dissociation pressure compound for semiconductors, comprising a saucer for holding a single volatile component constituting the high dissociation pressure compound.

Next, the apparatus of the present invention will be specifically explained with reference to the drawings. FIG. 2 is a schematic longitudinal sectional view of a bag counterfeit according to the present invention.

As shown in the figure, [a] The shape of the quartz crucible 2' holding the high dissociation pressure compound melt 8 and the boron oxide melt 16 for coating it has been simplified.

{b) A quartz furnace core tube 17 whose lower end has an outer diameter smaller than the inner diameter of the crucible 2' is supported on the support stand 20, and this furnace core tube 17 is supported on the crucible 2' and/or the support stand. 2
The lower end of the furnace core tube always aligns directly with the predetermined position in the boron oxide melt 16 for coating, following the drop in the liquid level of the high dissociation pressure compound melt 8 due to the vertical movement of the single crystal. It must be supported so that its vertical position can be adjusted freely.

[c- The iron-filled lid 4 that holds the sealing boron oxide melt 5 is made of Mo or Mo alloy.

{d} The volatile component alone 19 for creating an atmosphere of volatile components constituting the high dissociation pressure compound (for example, phosphorus if the high dissociation pressure compound is gallium silicide) in the furnace core tube 17
A saucer 18 for holding the is provided on the rotary pulling shaft 6 in the furnace core tube 17. 'e} If necessary, at least the part of the furnace core tube 17 immersed in the boron oxide melt for coating is made to hardly react with volatile components in the boron oxide melt 16 and the Takato pressure compound melt 8 (elutriation). Reactive) coated with a protective layer.

The above points [a' to [e'] are the same as the conventional single crystal manufacturing apparatus shown in FIG. , the above explanation will be used and duplicate explanation will be omitted.

Therefore, according to the device of the present invention, 'a} the volatile component 19 held in the saucer 18
is heated by the after-heater 3 and vaporized, so
The interior of the furnace core tube 17 becomes an atmosphere of the volatile components, and the growth of the single crystal occurs in the atmosphere of the volatile components. Therefore, the volatile components dissociate from the surface of the growing single crystal and the single crystal grows. Crystallinity near the crystal surface is not inhibited.

{b) Since the high dissociation pressure compound melt 8 is coated with the oxidized boron solution 16, evaporation from the high dissociation pressure compound melt is significantly suppressed, and as a result, evaporation from the high dissociation pressure compound melt to the inner surface of the heating wall of the furnace core tube 17 is Since the adhesion of evaporated substances is extremely reduced, internal observation is not obstructed, and even if a small amount of substances adhering to the inner surface of the heating wall peels off and falls, it will not be possible to remove the substances on the coating boron oxide melt 16. Since the single crystal growth conditions are not inhibited, the single crystallization rate can be dramatically improved.

'c} The lower end of the furnace core tube 17 has an outer diameter smaller than the inner diameter of the crucible 2', and the lower end of the furnace core tube 17 is always at a predetermined position in the coating boron oxide melt 16. Since the crucible 2' and/or the support stand 20 are installed so as to be able to move up and down and adjust their positions, even if vibrations are caused to the furnace core tube 17, the vibrations will not be transmitted to the crucible 2 at all, and the shape of the crucible Because the crucible can be simplified, the manufacturing cost is significantly lower than the bottle-shaped rotating crucible 2 in the secondary single crystal production equipment, and there is no need to use a particularly large crucible when producing single crystals in large quantities. Not only that, but the pressure difference that occurs inside and outside the furnace core tube 17 is absorbed by the vertical movement of the melt surface of the oxidized oxide shaft liquid 16, and the pressure applied to the inner and outer surfaces of the furnace core tube is always the same. Therefore, there is almost no deformation of the furnace core tube.

{d) The overhanging lid 4 that houses the sealing boron oxide melt 5 is made of Mo or Mo alloy, which exhibits excellent corrosion resistance against the boron oxide melt and high-temperature volatile components. , Semi-permanent use of the iron-fitted lid 4 is possible, and sufficient airtightness can be ensured by making the iron-fitted lid 4 fit against the masonry hearth tube 17.

{c' Receiver (preferably made of Mo or Mo alloy) 1 for holding the volatile component 19 constituting the high dissociation pressure compound installed in the rotary pulling vat 6 in the furnace core tube 17
8, an atmosphere of the volatile components is formed in the furnace core tube, and the boron oxide melt flowing down from the wisteria-filling lid 4 along the rotating lifting shaft 6 is collected. , the growing single crystal is not adversely affected by these flowing boron oxide melts.

This brings about industrially useful effects such as increasing the size of single crystals, increasing the size of single crystals, shortening manufacturing time, and improving mass productivity such as improving single crystallization rate, as well as crystallization such as lowering dislocations. This makes it possible to produce high dissociation pressure compound single crystals for semiconductors at low production costs while improving properties.

[Brief explanation of the drawing]

Figure 1 is a schematic vertical cross-sectional view showing a conventional single crystal manufacturing equipment;
The figure is a schematic vertical sectional view showing a single crystal manufacturing apparatus of the present invention. In the drawings, 1...metal container, 2...
・Bottle-shaped quartz rotating crucible, 2'...Simple-shaped quartz crucible, 3...After heater, 4...
...Iron-inserted lid, 5...Boron oxide melt for sealing, 6...Rotating pulling shaft, 7...Main heater, 8...・・High dissociation pressure compound melt, 9・・
... Rotating axis, 11 ... Chuck, 12 ...
...Seed crystal, 13...Inert gas introduction system,
14... Exhaust system, 15... Growth single crystal, 16... Oxidized borax liquid for coating, 17...
...Quartz hearth tube, 18...Saucer, 19.
... Volatile component alone, 20 ... Furnace core tube support stand. Figure 2

Claims (1)

[Scope of Claims] 1. A crucible supported at the upper end of a rotating shaft and holding a high dissociation pressure compound melt and a boron oxide melt for coating it, and a boron oxide melt for sealing at the upper end. A state in which the lower end has a fitting lid made of Mo or Mo alloy that holds the liquid and has an outer diameter smaller than the inner diameter of the crucible and is immersed in the boron oxide melt for coating the high dissociation pressure compound melt. a rotating pulling shaft that passes through the quartz furnace core tube and is attached to the shaft so that it can be rotated and pulled up freely, and has a seed crystal attached to its tip, and the quartz furnace core An apparatus for producing a single crystal of a high dissociation pressure compound for semiconductors, comprising: a saucer for holding a single volatile component constituting the high dissociation pressure compound, the tray being fixed to the rotational pulling shaft in a tube. . 2. In the apparatus for producing a single crystal of a high dissociation pressure compound for semiconductors as set forth in claim 1 above, at least the portion of the quartz furnace core tube immersed in the boron oxide melt for coating is immersed in the boron oxide melt and 1. An apparatus for producing a single crystal of a high dissociation pressure compound for semiconductors, characterized in that the single crystal is coated with a protective layer made of a material that is difficult to react with volatile components in a melt of the high dissociation pressure compound.