US3678893A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Improved device for supporting semiconductor wafers
Assignee: Stewart Warner Corp
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Filing: 1970-05-01
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Granted: 1972-07-25
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Expires: 1990-05-01
Abstract
Abstract A supporting device for semiconductor wafers to be used during deposition and diffusion process steps by which the wafers are oriented at an upward sloping angle in the direction of gas flow. The wafers are loaded on the devices so that the surfaces at which the semiconductor devices are being fabricated are facing downward and towards the downstream end to thereby provide an even gas flow across the face of each wafer and prevent the deposit on the desired surfaces of any contaminants which might be knocked loose from the interior surface of the reaction tube.
Inventors
- 👤 Harvey W Bell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:45
CPC Classifications
C; C30; C30B; C30B31/00; C30B31/06; C30B31/16; C30B25/00; C30B25/02; C30B25/12; C30B25/14; C30B31/14; H; H10; H10P; H10P95/00; Y; Y10; Y10S; Y10S206/00; Y10S206/832
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
342 words
A boat for use in supporting a plurality of semiconductor discs in spaced positions along the horizontal axis of a substantially horizontal reaction tube having a gas flowing from a position upstream of said boat to a position downstream of said boat, the improvement comprising a pair of spaced apart parallel quartz rails spaced for insertion in said tube with the elongate axis of each rail parallel to the horizontal axis of said tube, a plurality of pairs of spaced apart parallel quartz struts extending between said rails with each pair of struts comprising a large diameter rod spaced upstream of a respective small diameter rod by a distance greater than the thickness of said discs whereby each pair of struts receive the lower end of a respective disc therebetween with the upper end of each disc located downstream of the lower end and the downstream side of each disc faces downwardly, a plurality of quartz spacing strips joining said rails and located below the axis of said rails, a quartz end piece for each end of said rails joining said rails to each other, and a pair of elongate spaced apart supporting rods parallel to and intermediate said rails joined to said end pieces only with said supporting rods located between the lower edge of said struts and the upper edge of said spacing strips to thereby permit gas flow between said supporting rods, spacing strips and struts, said elongate supporting rods spaced apart by a distance less than the diameter of said discs to prevent passage of said discs therebetween and the spacing between said larger and smaller diameter supporting rods controlling the angle at which said discs are supported relative the axis whereby the downstream side of said discs tangentially engage a respective one of said smaller diameter rods and the rear downwardly facing sides of said discs are protected from the deposit of impurities from said tube while enabling said gas to deposit impurity dopant on said downstream sides and enable rapid cooling of said boat and discs.
Claim 2
Dependent Claim
342 words
A boat for use in supporting a plurality of semiconductor discs in spaced positions along the horizontal axis of a substantially horizontal reaction tube having a gas flowing from a position upstream of said boat to a position downstream of said boat, the improvement comprising a pair of spaced apart parallel quartz rails spaced for insertion in said tube with the elongate axis of each rail parallel to the horizontal axis of said tube, a plurality of pairs of spaced apart parallel quartz struts extending between said rails with each pair of struts comprising a large diameter rod spaced upstream of a respective small diameter rod by a distance greater than the thickness of said discs whereby each pair of struts receive the lower end of a respective disc therebetween with the upper end of each disc located downstream of the lower end and the downstream side of each disc faces downwardly, a plurality of quartz spacing strips joining said rails and located below the axis of said rails, a quartz end piece for each end of said rails joining said rails to each other, and a pair of elongate spaced apart supporting rods parallel to and intermediate said rails joined to said end pieces only with said supporting rods located between the lower edge of said struts and the upper edge of said spacing strips to thereby permit gas flow between said supporting rods, spacing strips and struts, said elongate supporting rods spaced apart by a distance less than the diameter of said discs to prevent passage of said discs therebetween and the spacing between said larger and smaller diameter supporting rods controlling the angle at which said discs are supported relative the axis whereby the downstream side of said discs tangentially engage a respective one of said smaller diameter rods and the rear downwardly facing sides of said discs are protected from the deposit of impurities from said tube while enabling said gas to deposit impurity dopant on said downstream sides and enable rapid cooling of said boat and discs.
References Cited (Backward Citations)
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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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |