US3723053A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat treating process for semiconductor fabrication
Assignee: SEMICONDUCTOR ELECT MEMORIES
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Filing: 1971-10-26
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Granted: 1973-03-27
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Expires: 1991-10-26
Abstract
Abstract A method and means for heat treating semiconductor material used in diffusion processes or in any semiconductor fabrication process, when the temperature of the semiconductor material exceeds its plastic temperature, for minimizing stresses caused by temperature gradients in the material whereby a number of harmful dislocations, which result in undesired electrical characteristics for the semiconductor circuits on the wafer are eliminated.
Inventors
- 👤 C Myers
- 👤 S Platter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 00:59
CPC Classifications
H; H10; H10P; H10P95/00; H10P95/90; Y; Y10; Y10S; Y10S148/00; Y10S148/003; Y10S148/06; Y10S148/071; Y10S148/097; Y10S148/121
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
43 words
A method of heat treating a semiconductor material for the purpose of avoiding dislocations comprising: increasing the temperature of said semiconductor material above the plastic deformation temperature of said semiconductor material, at a rate below the critical thermal stress rate for said material.
Claim 2
Independent Claim
43 words
A method of heat treating a semiconductor material for the purpose of avoiding dislocations comprising: increasing the temperature of said semiconductor material above the plastic deformation temperature of said semiconductor material, at a rate below the critical thermal stress rate for said material.
Claim 3
Independent Claim
86 words
A method of heating semiconductor wafers which are moved through a diffusion furnace in a manner to prevent dislocation caused by thermal stress comprising: spacing said wafers apart from one another in said boat a distance required for enabling said wafers to be heated through their sides, maintaining said furnace temperature as said wafers are moved therethrough at a value such that the rate of change of temperature through said semiconductor material does not exceed the critical value above the plastic deformation temperature of said material.
Claim 4
Independent Claim
86 words
A method of heating semiconductor wafers which are moved through a diffusion furnace in a manner to prevent dislocation caused by thermal stress comprising: spacing said wafers apart from one another in said boat a distance required for enabling said wafers to be heated through their sides, maintaining said furnace temperature as said wafers are moved therethrough at a value such that the rate of change of temperature through said semiconductor material does not exceed the critical value above the plastic deformation temperature of said material.
Claim 5
Independent Claim
92 words
A method of preventing dislocations in semiconductor wafers which are loaded on edge in a boat and then are moved through a diffusion furnace to be heat treated thereby comprising: heating the wafers to a temperature just below the plastic deformation temperature, moving the semiconductors through the processing zone of the furnace which has a temperature in excess of a plastic deformation temperature at a speed such that the rate of change of temperature in the material of the semiconductors does not exceed the rate which causes thermal stress in said material.
Claim 6
Independent Claim
92 words
A method of preventing dislocations in semiconductor wafers which are loaded on edge in a boat and then are moved through a diffusion furnace to be heat treated thereby comprising: heating the wafers to a temperature just below the plastic deformation temperature, moving the semiconductors through the processing zone of the furnace which has a temperature in excess of a plastic deformation temperature at a speed such that the rate of change of temperature in the material of the semiconductors does not exceed the rate which causes thermal stress in said material.
Claim 7
Dependent Claim
27 words
A method as recited in claim 3 wherein the semiconductor wafers are moved through the furnace at a velocity which matches the temperature profile of the furnace.
Claim 8
Dependent Claim
85 words
The method as recited in claim 3 wherein the temperature gradient between the center and the edge of the semiconductor wafers in said boat are measured as said boat passes through said furnace to produce a temperature differential value, comparing the temperature differential value with a critical temperature differential value to provide a control voltage, and controlling the velocity of the motion of said semiconductor material through said furnace responsive to said control voltage to maintain said temperature differential below said critical temperature differential value.
Claim 9
Dependent Claim
82 words
The method as recited in claim 3 wherein the temperature gradient between the center and edge of the semiconductor wafers in said boat are measured as said boat passes through said furnace to produce a temperature differential value, comparing the temperature differential value with a critical temperature differential value to establish a control voltage, and controlling the power applied for heating said furnace for changing the furnace temperature at a value which maintains said temperature differential below said critical temperature differential value.
Claim 10
Independent Claim
84 words
A method of preventing dislocations in semiconductor wafers which are loaded on edge in a boat and then are moved through a diffusion furnace to be heat treated thereby comprising: heating said semiconductor wafers to a temperature below the temperature at which plastic deformation of said semiConductor wafer material occurs, measuring the temperature of said furnace, controlling the power applied for heating said furnace for changing the furnace temperature at a value which does not cause thermal stresses to occur in said semiconductor wafers.
Claim 11
Independent Claim
84 words
A method of preventing dislocations in semiconductor wafers which are loaded on edge in a boat and then are moved through a diffusion furnace to be heat treated thereby comprising: heating said semiconductor wafers to a temperature below the temperature at which plastic deformation of said semiConductor wafer material occurs, measuring the temperature of said furnace, controlling the power applied for heating said furnace for changing the furnace temperature at a value which does not cause thermal stresses to occur in said semiconductor wafers.
References Cited (Backward Citations)
US3461547A
Cited
US3620520A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |