US4494300A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for forming transistors using silicon ribbons as substrates
Assignee: International Business Machines Corp
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Filing: 1981-06-30
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Granted: 1985-01-22
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Expires: 2001-06-30
Abstract
Abstract A process improvement for enabling the development of low cost transistor devices, particularly MOS FETs, in annealed polysilicon formed on an insulator; the improvement resulting from the use of silicon ribbons as substrates.
Inventors
- 👤 Guenter H. Schwuttke
- 👤 Kuei H. Yang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:57
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/0312; H10D30/0314; H10D30/0321; H10D86/00; H10D86/201; H10P; H10P34/00; H10P34/40; H10P34/42; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1912; H10W; H10W10/00; H10W10/10; H10W10/181
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
97 words
A process of forming a semiconductor monolithic structure comprising: providing a semicrystalline ribbon of silicon having a thickness substantially less than 0.5 millimeters and having a suitable defect structure which favors strain-induced recrystallization; thermally forming a silicon dioxide layer on a surface of said ribbon; forming an active device layer of polysilicon over said oxide layer; and annealing said polysilicon layer to induce localized melting and recrystallization of said polysilicon layer whereby uniform crystals of larger grain size than those initially formed are effected in the polysilicon layer due to said defect structure in said semicrystalline ribbon.
Claim 2
Dependent Claim
97 words
A process of forming a semiconductor monolithic structure comprising: providing a semicrystalline ribbon of silicon having a thickness substantially less than 0.5 millimeters and having a suitable defect structure which favors strain-induced recrystallization; thermally forming a silicon dioxide layer on a surface of said ribbon; forming an active device layer of polysilicon over said oxide layer; and annealing said polysilicon layer to induce localized melting and recrystallization of said polysilicon layer whereby uniform crystals of larger grain size than those initially formed are effected in the polysilicon layer due to said defect structure in said semicrystalline ribbon.
Claim 3
Dependent Claim
43 words
A process as defined in claim 1, in which said semicrystalline ribbon of silicon has a thickness of approximately 200 microns, said silicon dioxide layer has a thickness of approximately 1500 Angstroms and said layer of polysilicon a thickness of approximately 4200 Angstroms.
Claim 4
Dependent Claim
20 words
A process as defined in claim 1, further comprising the step of forming active devices in the recrystallized polysilicon layer.
Claim 5
Dependent Claim
15 words
A process as defined in claim 3 in which said active devices are MOS FETS.
Claim 6
Dependent Claim
19 words
A process as defined in claim 1, in which said annealing step is achieved by means of a laser.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-22 | 1988-07-23 | 1989-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-22 | 1992-07-23 | 1993-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-22 | 1996-07-23 | 1997-01-22 | $7700.00 | Window Closed / Lapsed |