US4125425A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing flat tapes of crystalline silicon from a silicon melt by drawing a seed crystal of silicon from the melt flowing down the faces of a knife shaped heated element
Assignee: US Philips Corp
•
Filing: 1977-02-28
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Granted: 1978-11-14
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Expires: 1997-02-28
Abstract
Abstract A method of manufacturing bodies from meltable crystalline material in which a continuous tape of said material is manufactured by causing melted material to flow along at least one surface of a heated element, which surface is wetted by the melted material, and causing the tape to grow by drawing away a second near the lower side of the surface. Application in particular to the manufacture of semiconductor bodies, for example of silicon.
Inventors
- 👤 Jean-Jacques L. E. Brissot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:30
CPC Classifications
C; C30; C30B; C30B15/00; C30B15/08; C30B11/00; C30B11/04; C30B11/08; C30B11/10; Y; Y10; Y10S; Y10S117/00; Y10S117/90; Y10S117/901; Y10S117/902; Y10S117/91
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
208 words
A method of manufacturing flat tapes of crystalline silicon, said method comprising contacting a supply of solid silicon with the upper surface of an element heated to the melting point of said silicon, to thereby convert said solid silicon into a molten silicon mass flowing downwardly over the outer surface of said heated element, said element being a cylinder having a horizontal axis, a first surface essentially parallel to said horizontal axis and two additional surfaces extending downwardly from the edges of said first surface and meeting each other at their lower edges to form a rectangular shaped rim, the surface of said element being resistant to the action of said molten silicon mass and at least said two downwardly extending surfaces and said rim being formed of a material wettable by said molten silicon mass, contacting said downwardly flowing molten silicon mass with a silicon crystal seed positioned at a small distance below the lower edge of said rectangular shaped rim to thereby wet the upper surface of said crystal seed with said downwardly flowing molten silicon mass and drawing said thus wetted seed crystal downwardly from said element to thereby cause said molten silicon mass to solidify and grow a downwardly extending flat crystalline silicon tape.
Claim 2
Independent Claim
208 words
A method of manufacturing flat tapes of crystalline silicon, said method comprising contacting a supply of solid silicon with the upper surface of an element heated to the melting point of said silicon, to thereby convert said solid silicon into a molten silicon mass flowing downwardly over the outer surface of said heated element, said element being a cylinder having a horizontal axis, a first surface essentially parallel to said horizontal axis and two additional surfaces extending downwardly from the edges of said first surface and meeting each other at their lower edges to form a rectangular shaped rim, the surface of said element being resistant to the action of said molten silicon mass and at least said two downwardly extending surfaces and said rim being formed of a material wettable by said molten silicon mass, contacting said downwardly flowing molten silicon mass with a silicon crystal seed positioned at a small distance below the lower edge of said rectangular shaped rim to thereby wet the upper surface of said crystal seed with said downwardly flowing molten silicon mass and drawing said thus wetted seed crystal downwardly from said element to thereby cause said molten silicon mass to solidify and grow a downwardly extending flat crystalline silicon tape.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein said element at least at its surface is formed of a refractory carbon containing material.
Claim 4
Dependent Claim
35 words
A method as claimed in claim 1, characterized in that the element at least at its surface is formed of a refractory material selected from the group consisting of carbon, silicon carbide, and titanium carbide.
Claim 5
Dependent Claim
42 words
A method as claimed in claim 1, characterized in that the element consists of a refractory conductive coil coated with a thin layer of a refractory non-conductive or high-ohmic material which has a high resistivity against the action of the molten material.
Claim 6
Dependent Claim
33 words
A method as claimed in claim 4, characterized in that the thin layer of the element consists of a material selected from the group consisting of silicon nitride, and very pure silicon carbide.
Claim 7
Dependent Claim
28 words
A method as claimed in claim 1, characterized in that the lower limit of the surface of the element along which the molten silicon mass flows is horizontal.
Claim 8
Dependent Claim
30 words
A method as claimed in claim 1, characterized in that the element along which the molten silicon mass flows has the form of a knife, in particular a balance knife.
Claim 9
Dependent Claim
33 words
A method as claimed in claim 1, characterized in that the shape of the element along which the molten silicon mass flows is that of a plate having parallel or substantially parallel surfaces.
Claim 10
Dependent Claim
44 words
A method as claimed in claim 1, characterized in that the element along which the molten silicon mass flows is heated at a temperature which is slightly higher than that of the melting point of the silicon material to be crystallized from the melt.
Claim 11
Dependent Claim
35 words
A method as claimed in claim 1, characterized in that the desired thickness of the tape of the crystalline silicon material is obtained by adjusting the thickness of the lower part of the heated element.
Claim 12
Dependent Claim
14 words
A method as claimed in claim 1, characterized in that the seed is flat.
Claim 13
Dependent Claim
32 words
A method as claimed in claim 1, characterized in that the drawing of the crystalline silicon tape is carried out at a rate in the order of a few millimeters per minute.
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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) | 1981-11-13 | 1982-05-15 | 1982-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-13 | 1986-05-15 | 1986-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-13 | 1990-05-15 | 1990-11-14 | $7700.00 | Window Closed / Lapsed |