Patent US3406002A successfully refreshed from Google Patents.
US3554162A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diffusion tube
Assignee: Motorola Solutions Inc
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Filing: 1969-01-22
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Granted: 1971-01-12
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Expires: 1989-01-22
Abstract
Abstract A diffusion tube is described which incorporates an internal seal to prevent the back diffusion of impurity material and the condensation thereof on the input portion of the tube. The tube is provided with an internal baffle plate which is urged into contact with a stop provided on the inner periphery of the tube. The baffle plate contains an aperture to permit the passage of gas therethrough from the input port of the tube. An impurity support is attached to the side of the baffle plate opposite the input port. The impurity source and the semiconductor wafers being processed are inserted in the same end of the diffusion tube. This end is relatively free from condensed impurity material at the completion of the diffusion process due to the combination of the shoulder and the baffle plate. As a result, the processed wafers can be withdrawn from the tube without significant surface contamination.
Inventors
- 👤 Marlo E Cota
- 👤 James H Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:43
CPC Classifications
C; C30; C30B; C30B31/00; C30B31/06; C30B31/10; C30B31/16; Y; Y10; Y10S; Y10S118/00; Y10S118/90
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
184 words
A diffusion chamber of the type utilized in the diffusion of impurities from an impurity source at relatively high temperatures into semiconductor bodies contained therein which comprises: a. an elongated tube having input and output ports located at the opposing end thereof; b. means for passing a carrier gas through at least a portion of said elongated tube; c. an inwardly extending refractory stop provided on and extending continuously around the inner periphery of said tube, said stop being located between the impurity source and the input port; d. an apertured refractory baffle disposed between said stop and said input port and adapted for engagement with said stop; e. a refractory extension tube affixed to said baffle plate about said aperture and extending from said baffle plate toward the input port, whereby said carrier gas passes over the impurity source; and f. biasing means coupled to said rod for urging said baffle plate into engagement with the stop whereby the combination of said baffle plate and stop substantially eliminate the deposition of impurities on the portion of said tube proximate to said input port.
Claim 2
Dependent Claim
184 words
A diffusion chamber of the type utilized in the diffusion of impurities from an impurity source at relatively high temperatures into semiconductor bodies contained therein which comprises: a. an elongated tube having input and output ports located at the opposing end thereof; b. means for passing a carrier gas through at least a portion of said elongated tube; c. an inwardly extending refractory stop provided on and extending continuously around the inner periphery of said tube, said stop being located between the impurity source and the input port; d. an apertured refractory baffle disposed between said stop and said input port and adapted for engagement with said stop; e. a refractory extension tube affixed to said baffle plate about said aperture and extending from said baffle plate toward the input port, whereby said carrier gas passes over the impurity source; and f. biasing means coupled to said rod for urging said baffle plate into engagement with the stop whereby the combination of said baffle plate and stop substantially eliminate the deposition of impurities on the portion of said tube proximate to said input port.
Claim 3
Dependent Claim
114 words
The diffusion chamber in accordance with claim 1 wherein said elongated refractory tube includes first and second tubular sections, each having first and second ends, the first end of said sections containing the input and output ports respectively, the second end of said first section having a cross section smaller than the cross section of the second end of the second section, to permit the insertion of a portion of said first section into said second section, the second end of said second section being sealed to the outer surface of said first section, the second end of said first section extending into said first section and forming the stop for the baffle plate.
Claim 4
Dependent Claim
49 words
The diffusion chamber in accOrdance with one of claims 1 further comprising a refractory feed tube located in the input port of said elongated tube, said feed tube being adapted for the passage of gas therethrough, and said biasing means being coupled between said feed tube and extension rod.
Claim 5
Dependent Claim
37 words
The diffusion chamber in accordance with claim 3 further comprising support means for an impurity source affixed to said baffle plate, said support means being located on the side of the baffle plate facing the output port.
Claim 6
Dependent Claim
51 words
The diffusion chamber in accordance with claim 4 wherein said feed tube and extension tube form a gap therebetween, said biasing means mounted in the gap between tubes and attached thereto to permit withdrawal of the combination of the baffle plate and extension tube by the movement of said feed tube.
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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) | 1974-01-11 | 1974-07-13 | 1975-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-11 | 1978-07-13 | 1979-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-11 | 1982-07-13 | 1983-01-12 | $7700.00 | Window Closed / Lapsed |