US3857679A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crystal grower
Assignee: University of Southern California
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Filing: 1973-02-05
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Granted: 1974-12-31
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Expires: 1993-02-05
Abstract
Abstract A crystal grower furnace assembly having a gastight housing, a crystal pulling rod extending into the housing coaxially with the vertical axis of the housing and the heating elements. The housing is divided into a first chamber adapted for growing a crystal by the Czochralski technique, from a melt of the crystalline material, a second chamber above the first chamber having a port for evacuation and admission of gases, and a narrow neck connecting the chambers in coaxial alignment. The rod extends through the neck and is adapted for rotational and vertical movement therein. One heater element, situated near the juncture of the neck portion and the second chamber, is employed to heat boron oxide to a liquid which is used to seal the space between the rod and the inner wall of the neck portion to seal off the first chamber from the second chamber during the crystal growth operation. The second heater is situated near the top of the first chamber and is employed to prevent the condensation of arsenic during crystal growth.
Inventors
- 👤 W Allred
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:15
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/16; F16J15/40; F16J15/403; C; C30; C30B; C30B15/00; C30B15/14; C30B15/30; Y; Y10; Y10S; Y10S117/00; Y10S117/90; Y10T; Y10T117/00; Y10T117/10; Y10T117/1016; Y10T117/1024; Y10T117/1032; Y10T117/106; Y10T117/1064
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
165 words
A FURNACE ASSEMBLY FOR THE GROWTH OF AN UNCONTAMINATED ARSENIDE COMPOUND CRYSTAL OF PREDETR ERMINED COMPOSITION INCLUDING: A GAS-TIGHT HOUSING, SAID HOUSING HAVING A FIRST CHAMBER ADAPTED FOR THE GROWTH OF CRYSTALS FROM A MELT BY THE CRYSTAL PULL TECHNIQUE, A SECOND CHAMBER AND A NECK INTERCONNECTING THE TWO CHAMBERS ALONG THE VERTICAL AXIS OF SAID HOUSING, SAID FIRST CHAMBER ADAPTED TO SUPPORT A MELT OF THE ARSENIDE COMPOUND FOR CRYSTAL GROWTH, SAID SECOND CHAMBER HAVING A CIRCULAR APERTURE COAXIAL WITH SAID AXIS AND A PORT FOR THE EVACUATION AND ADMISSION OF GAS OUT OF AND INTO SAID HOUSING, SAID NECK HAVING A CIRCULAR BORE COAXIAL WITH SAID AXIS AND COMMUNICATING WITH SAID CHAMBERS; A CYLINDRICAL ROD PASSING THROUGH SAID APERTURE INTO SAID HOUSING COAXIAL WITH SAID AXIS, THE LOWER END OF SAID ROD EXTENDING INTO SAID FIRST CHAMBER, SAID ROD JOURNALED IN SAID BORE AND ADAPTED FOR ROTATION ABOUT AND VERTICAL MOVEMENT ALONG SAID AXIS FOR THE GROWTH OF A CRYSTAL FROM THE MELT;
Claim 2
Dependent Claim
165 words
A FURNACE ASSEMBLY FOR THE GROWTH OF AN UNCONTAMINATED ARSENIDE COMPOUND CRYSTAL OF PREDETR ERMINED COMPOSITION INCLUDING: A GAS-TIGHT HOUSING, SAID HOUSING HAVING A FIRST CHAMBER ADAPTED FOR THE GROWTH OF CRYSTALS FROM A MELT BY THE CRYSTAL PULL TECHNIQUE, A SECOND CHAMBER AND A NECK INTERCONNECTING THE TWO CHAMBERS ALONG THE VERTICAL AXIS OF SAID HOUSING, SAID FIRST CHAMBER ADAPTED TO SUPPORT A MELT OF THE ARSENIDE COMPOUND FOR CRYSTAL GROWTH, SAID SECOND CHAMBER HAVING A CIRCULAR APERTURE COAXIAL WITH SAID AXIS AND A PORT FOR THE EVACUATION AND ADMISSION OF GAS OUT OF AND INTO SAID HOUSING, SAID NECK HAVING A CIRCULAR BORE COAXIAL WITH SAID AXIS AND COMMUNICATING WITH SAID CHAMBERS; A CYLINDRICAL ROD PASSING THROUGH SAID APERTURE INTO SAID HOUSING COAXIAL WITH SAID AXIS, THE LOWER END OF SAID ROD EXTENDING INTO SAID FIRST CHAMBER, SAID ROD JOURNALED IN SAID BORE AND ADAPTED FOR ROTATION ABOUT AND VERTICAL MOVEMENT ALONG SAID AXIS FOR THE GROWTH OF A CRYSTAL FROM THE MELT;
Claim 3
Dependent Claim
33 words
The furnace assembly as defined in claim 1 including a heating means external of said housing for maintaining the crystal grown from the melt at a predetermined annealing temperature in said first chamber.
Claim 4
Dependent Claim
16 words
The furnace assembly as defined in claim 1 wherein said inert sealant means is boron oxide.
Claim 5
Dependent Claim
18 words
The furnace assembly as defined in claim 1 including means for holding the melt in said first chamber.
Claim 6
Dependent Claim
274 words
A furnace assembly for the growth of an uncoNtaminated arsenide compound crystal of predetermined composition, including: a gas-tight quartz housing, said housing having a first chamber adapted for the growth of crystals from a melt by the crystal pull technique, a second chamber and a neck interconnecting the two chambers along the vertical axis of said housing, said first chamber adapted to support a melt of the arsenide compound for crystal growth, said second chamber having a circular aperture coaxial with said axis and a port for the evacuation and admission of gas out of and into said housing, and said neck having a circular bore coaxial with said axis communicating with said chamber; a cylindrical rod passing through said aperture into said housing coaxial with said axis, said rod journaled into said bore and adapted for rotation about and vertical movement along said axis in said housing for the growth of a crystal from the melt; means external of said housing for rotating and vertically moving said rod for crystal growth; a predetermined amount of boron oxide in said housing, said boron oxide being stored as a solid at ambient temperature in said second chamber prior to the operation of said assembly, and said boron oxide sealing the space between said rod and the internal wall of said bore as a liquid at elevated temperatures; means external of said housing for heating and melting said boron oxide; means external of said housing for heating the melt of the arsenide compound; and means external of said housing for maintaining the crystal grown from the melt at a predetermined annealing temperature in said first chamber.
Claim 7
Dependent Claim
274 words
A furnace assembly for the growth of an uncoNtaminated arsenide compound crystal of predetermined composition, including: a gas-tight quartz housing, said housing having a first chamber adapted for the growth of crystals from a melt by the crystal pull technique, a second chamber and a neck interconnecting the two chambers along the vertical axis of said housing, said first chamber adapted to support a melt of the arsenide compound for crystal growth, said second chamber having a circular aperture coaxial with said axis and a port for the evacuation and admission of gas out of and into said housing, and said neck having a circular bore coaxial with said axis communicating with said chamber; a cylindrical rod passing through said aperture into said housing coaxial with said axis, said rod journaled into said bore and adapted for rotation about and vertical movement along said axis in said housing for the growth of a crystal from the melt; means external of said housing for rotating and vertically moving said rod for crystal growth; a predetermined amount of boron oxide in said housing, said boron oxide being stored as a solid at ambient temperature in said second chamber prior to the operation of said assembly, and said boron oxide sealing the space between said rod and the internal wall of said bore as a liquid at elevated temperatures; means external of said housing for heating and melting said boron oxide; means external of said housing for heating the melt of the arsenide compound; and means external of said housing for maintaining the crystal grown from the melt at a predetermined annealing temperature in said first chamber.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |