US3129125A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of silicon carbide materials
Assignee: Westinghouse Electric Corp
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Filing: 1959-07-01
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Granted: 1964-04-14
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Expires: 1979-07-01
Abstract
No abstract record available.
Inventors
- 👤 Donald R Hamilton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:30
CPC Classifications
C; C30; C30B; C30B23/00; C30B29/00; C30B29/10; C30B29/36; Y; Y10; Y10S; Y10S117/00; Y10S117/906; Y10S148/00; Y10S148/148; Y10S438/00; Y10S438/914; Y10S438/919; Y10S438/925; Y10S438/931
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
116 words
IN A MEHTOD OF PREPARING SILICON CARBIDE SINGLE CRYSTALS CONTAINING AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF ALUMINUM AND BORON AS THE SIGNIFICANT, P-TYPE CONDUCTIVITY DETERMINING IMPURITY IN A PORTION THEREOF, IN WHICH A RAW MATERIAL CHARGE CONTAINING SAID ELEMENT IS HEATED TO A TEMPERATURE SUFFICIENT TO PRODUCE A VAPOR OF SILICON NUCLEATE AND GRO THEREFROM, THE STEP OF DECREASING THE CONCENTRATION OF P-TYPE IMPURITY PRESENT IN A PREDETERMINED SUBSEQUENTLY GROWN PORTION OF THE CRYSTALS BEING SO PRODUCED COMPRISING FLOWING AN INERT GAS COMPRISING CHLORINE INTO THE AREA OF CRYSTAL GROWTH AT THE TIME SAID PREDETERMINED PORTION OF SAID CRYSTALS IS GROWING WHEREBY THE CONCENTRATION OF THE P-TYPE ELEMENT IN THE SUBSEQUENT PORTION IS REDUCED.
Claim 2
Dependent Claim
116 words
IN A MEHTOD OF PREPARING SILICON CARBIDE SINGLE CRYSTALS CONTAINING AN ELEMENT SELECTED FROM THE GROUP CONSISTING OF ALUMINUM AND BORON AS THE SIGNIFICANT, P-TYPE CONDUCTIVITY DETERMINING IMPURITY IN A PORTION THEREOF, IN WHICH A RAW MATERIAL CHARGE CONTAINING SAID ELEMENT IS HEATED TO A TEMPERATURE SUFFICIENT TO PRODUCE A VAPOR OF SILICON NUCLEATE AND GRO THEREFROM, THE STEP OF DECREASING THE CONCENTRATION OF P-TYPE IMPURITY PRESENT IN A PREDETERMINED SUBSEQUENTLY GROWN PORTION OF THE CRYSTALS BEING SO PRODUCED COMPRISING FLOWING AN INERT GAS COMPRISING CHLORINE INTO THE AREA OF CRYSTAL GROWTH AT THE TIME SAID PREDETERMINED PORTION OF SAID CRYSTALS IS GROWING WHEREBY THE CONCENTRATION OF THE P-TYPE ELEMENT IN THE SUBSEQUENT PORTION IS REDUCED.
References Cited (Backward Citations)
US2854364A
Cited
US2918396A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-04-14 | 1967-10-14 | 1968-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-04-14 | 1971-10-14 | 1972-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-04-14 | 1975-10-14 | 1976-04-14 | $7700.00 | Window Closed / Lapsed |