EP0159113A1
Expired / Lapsed
EP
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Process and apparatus for growing single crystals of III - V compound semiconductor
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1985-02-21
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Granted: —
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Expires: 2005-02-21
Abstract
Abstract A part of the melt surface (21) of a starting material is covered with an encapsulant (22) and the rest thereof (23) is directly in contact with the gas atmosphere in the vessel (1), and for that purpose the apparatus comprises a means (20) for dividing the space in the crucible (4) into two parts, which consequently divides the melt (15) surface into two sections (21, 23). In order to obtain the best quality single crystal (16), of the III - V compound semiconductor having a high dissociation pressure, by the use of a vertical puller, it is nessesary to enjoy the impurity capture effect of the encapsulant (22) and to equilibrate the vapour pressure of the group V element in the vessel (1) and the dissociation pressure of the melt during the growth procedure, these procedure being able to be accomplished by the use of the apparatus (vertical puller) comprising a means (20) for dividing the melt surface.
Inventors
- 👤 Koji Tada
- 👤 Masami Tatsumi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 18:12
CPC Classifications
C; C30; C30B; C30B27/00; C30B27/02; C30B29/00; C30B29/10; C30B29/40
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
75 words
A process for preparing single crystals of III-V compound semiconductor which comprises pulling a seed crystal which is in contact with the melt of a starting material contained in a crucible placed in a sealable vessel under the gas atmosphere of a group V element, characterized by, during growth of the single crystal, covering a part of the melt surface with a liquid encapsulant while maintaining the rest thereof in contact with the gas atmosphere.
Claim 2
Dependent Claim
75 words
A process for preparing single crystals of III-V compound semiconductor which comprises pulling a seed crystal which is in contact with the melt of a starting material contained in a crucible placed in a sealable vessel under the gas atmosphere of a group V element, characterized by, during growth of the single crystal, covering a part of the melt surface with a liquid encapsulant while maintaining the rest thereof in contact with the gas atmosphere.
Claim 3
Dependent Claim
108 words
A process as set forth in claim 1, wherein the covering of the melt with the encapsulant is effected by the steps of: loading the starting material in the crucible; introducing a means for dividing the space in the crucible, which consequently acts as a means for divinding the melt surface into two sections; partially melting the starting material so that the lower portion of the dividing means is uniformly immersed in the thus formed melt; cooling the thus formed melt to solidify; loading the encapsulant on one section of the surface of the solidified starting material; and reheating crucible to melt the starting material and the encapsulant.
Claim 4
Dependent Claim
134 words
A process as set forth in claim 1, wherein the covering of the melt with the encapsulant is effected by the steps of: dividing the space in the crucible into two parts by a divinding means, which consequently acts as a means for dividing the melt surface into two sections during the crystal growth; closely charging the starting material into at least one section of the crucible, in the form of poder or in the form of molded piece having a dimention slightly smaller than the inner dimension of the dividing means or loading molded pieces into holes or apertures of dividing means; charging the encapsulant and the rest of the starting material into the crucible; introducing the crucible into the vessel; and heating the starting material and the solid encapsulant to melt down.
Claim 5
Independent Claim
142 words
An apparatus for growing single crystals of III-V compound semiconductor comprises a tight sealable vessel, a crucible to be placed in the vessel, an upper shaft for pulling and rotating the grown crystal; a lower shaft for supporting and rotating the crucible to ensure rotation of the melt of starting materials contained therein; a plurality of heaters mounted around the vessel in its longitudinal direction to ensure a desired temperature distribution in the entire vessel, said apparatus being characterized by further comprising a means for dividing the space in the crucible into two parts, which consequently acts as a means for dividing the surface of the melt into two sections, so that one section of the melt surface is covered with a liquid encapsulant and the other section is directly in contact with the atmosphere in the vessel during the crystal growth.
Claim 6
Independent Claim
142 words
An apparatus for growing single crystals of III-V compound semiconductor comprises a tight sealable vessel, a crucible to be placed in the vessel, an upper shaft for pulling and rotating the grown crystal; a lower shaft for supporting and rotating the crucible to ensure rotation of the melt of starting materials contained therein; a plurality of heaters mounted around the vessel in its longitudinal direction to ensure a desired temperature distribution in the entire vessel, said apparatus being characterized by further comprising a means for dividing the space in the crucible into two parts, which consequently acts as a means for dividing the surface of the melt into two sections, so that one section of the melt surface is covered with a liquid encapsulant and the other section is directly in contact with the atmosphere in the vessel during the crystal growth.
Claim 7
Dependent Claim
39 words
An apparatus as set forth in claim 4 wherein the dividing means is consituted by a material selected from the group consisting of quarz, vitreous carbon, BN, AlN, SiC or those coated with pyrolitic boron nitride or B N.
Claim 8
Dependent Claim
32 words
An apparatus as set forth in claim 5, in which the means for dividing the melt surface is an elongated hollow member having a sectional dimension less than that of the crucible.
Claim 9
Dependent Claim
28 words
An apparatus as set forth in claim 6, in which said hollow member has a plurality of apertures or holes on the lower part of the side wall.
Claim 10
Dependent Claim
23 words
8 . An apparatus as set forth in claim 6, wherein said hollow member is fixed on the side wall of the crucible.
Claim 11
Dependent Claim
26 words
An apparatus as set forth in claim 6, wherein said hollow member is supported by a supporter or by legs fixed to the lower end thereof.
References Cited (Backward Citations)
DE1934369A1
Cited
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