US3853974A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing a hollow body of semiconductor material
Assignee: Siemens AG
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Filing: 1973-02-21
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Granted: 1974-12-10
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Expires: 1993-02-21
Abstract
Abstract An at least unilaterally open hollow body of silicon or other semiconductor material is produced by thermally reducing a gaseous compound of the same material and precipitating the segregated material upon a heated carrier of different material, preferably graphite or other industrial carbon, and thereafter removing the resulting hollow semiconductor body from the carrier. The gaseous compound is supplied to the heated carrier in mixture with a reduction gas, preferably hydrogen, in a molar ratio that substantially corresponds to the reaction equilibrium at the carrier temperature obtaining at the beginning of the reduction and precipitation process. After the precipitated hollow body has reached a layer thickness of a few microns, the molar ratio is changed so as to increase the rate of precipitation. The method can be modified by changing the throughput of the gaseous mixtures from a lower to a higher value after a layer thickness of a few microns has been reached and then continuing the precipitation at a higher rate until the desired full layer thickness is obtained.
Inventors
- 👤 K Reuschel
- 👤 W Dietze
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:10
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/22; C23C16/24; C01; C01B; C01B33/00; C01B33/02; C23C16/01; Y; Y10; Y10S; Y10S148/00; Y10S148/007; Y10S148/025; Y10S148/027; Y10S148/049; Y10S148/073; Y10S148/122
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
223 words
THE METHOD OF PRODUCING AN AT LEAST UNILATERALLY OPEN, HOLLOW BODY OF SILICON BY THERMALLY REDUCING A GASEOUS CARRIER HALIDE OR HYDRIDE OF SILICON AND PRECIPITATING THE SEGREGATING SILICON UPON A GRAPHITE CARRIER HEATED TO THE SEGREGATING TEMPERATURE OF THE GASEOUS CARRIER AND THEREAFTER REMOVING THE GRAPHITE CARRIER FROM THE RESULTING HOLLOW SILLICON BODY, SAID METHOD COMPRISING THE STEPS OF SUPPLYING TO THE HEATED GRAPHITE CARRIER A MIXTURE OF HYDROGEN AND SAID GASEOUS CARRIER HALIDE OR HYDRIDE OF SILICON IN A MOLAR RATIO OF SAID HYDROGEN TO SAID GASEOUS CARRIER WITHIN THE RANGE FROM 1:0.005 AND 1:0.5 CORRESPONDING SUBSTANTIALLY TO THE REACTION EQUILIBRIUM AT THE SEGREGATION TEMPERATURE TO THEREBY AVOID THE FORMATION OF CRYSTALLITES OR DENDRITES, APPLYING A FLOW RATE TO PRECIPITATW 0.002 - 0.1 G SI/H CM2, WHEREIN SI DENOTES SILICON, H DENOTES A TIME UNIT OF ONE HOUR AND CM2 DENOTES A SURFACE UNIT OF ONE SQUARE CENTIMETER AND RELATES TO THE SURFACE AREA UPON WHICH THE SEMICONDUCTOR MATERIAL IS TO BE PRECIPITATED UNTIL THE PRECIPITATED SILICON BODY HAS REACHED A LAYER THICKNESS OF AT LEAST 1 MICRON; AND THEREAFTER INCREASING THE FLOW RATE OF THE MIXTURE TO INCREASE THE RATE OF PRECIPITATION ABOVE THE RATE OF PRECIPITATION IN FORMING SAID LAYER THICKNESS OF AT LEAST 1 MICRON TO AN AMOUNT WITHIN THE RANGE OF 0.05 - 0.2 G SI/H CM2.
Claim 2
Independent Claim
223 words
THE METHOD OF PRODUCING AN AT LEAST UNILATERALLY OPEN, HOLLOW BODY OF SILICON BY THERMALLY REDUCING A GASEOUS CARRIER HALIDE OR HYDRIDE OF SILICON AND PRECIPITATING THE SEGREGATING SILICON UPON A GRAPHITE CARRIER HEATED TO THE SEGREGATING TEMPERATURE OF THE GASEOUS CARRIER AND THEREAFTER REMOVING THE GRAPHITE CARRIER FROM THE RESULTING HOLLOW SILLICON BODY, SAID METHOD COMPRISING THE STEPS OF SUPPLYING TO THE HEATED GRAPHITE CARRIER A MIXTURE OF HYDROGEN AND SAID GASEOUS CARRIER HALIDE OR HYDRIDE OF SILICON IN A MOLAR RATIO OF SAID HYDROGEN TO SAID GASEOUS CARRIER WITHIN THE RANGE FROM 1:0.005 AND 1:0.5 CORRESPONDING SUBSTANTIALLY TO THE REACTION EQUILIBRIUM AT THE SEGREGATION TEMPERATURE TO THEREBY AVOID THE FORMATION OF CRYSTALLITES OR DENDRITES, APPLYING A FLOW RATE TO PRECIPITATW 0.002 - 0.1 G SI/H CM2, WHEREIN SI DENOTES SILICON, H DENOTES A TIME UNIT OF ONE HOUR AND CM2 DENOTES A SURFACE UNIT OF ONE SQUARE CENTIMETER AND RELATES TO THE SURFACE AREA UPON WHICH THE SEMICONDUCTOR MATERIAL IS TO BE PRECIPITATED UNTIL THE PRECIPITATED SILICON BODY HAS REACHED A LAYER THICKNESS OF AT LEAST 1 MICRON; AND THEREAFTER INCREASING THE FLOW RATE OF THE MIXTURE TO INCREASE THE RATE OF PRECIPITATION ABOVE THE RATE OF PRECIPITATION IN FORMING SAID LAYER THICKNESS OF AT LEAST 1 MICRON TO AN AMOUNT WITHIN THE RANGE OF 0.05 - 0.2 G SI/H CM2.
Claim 3
Dependent Claim
29 words
The method as claimed in claim 1, wherein the initial slow rate of silicon precipitation is about 0.05 g Si/cm2h and the increased rate is about 0.1 g Si/cm2h.
Claim 4
Dependent Claim
76 words
The method as claimed in claim 1, wherein the gaseous halide is SiCl4, and further comprising setting at a reaction temperature of about 1,200*C the molar ratio of hydrogen to SiCl4 to within the range from 1:0.005 to 1:0.05, initially maintaining a reduced throughput of 0.05 - 2.5 liters/h cm2 until the precipitated layer of silicon has reached a thickness of at least about 1 micron, and thereafter applying a throughput of about 5 liters/h cm2.
Claim 5
Dependent Claim
77 words
The method as claimed in claim 1, wherein the gaseous halide is SiH2Cl2, and further comprising setting at a reaction temperature of about 1,100*C the molar ratio of hydrogen gas to SiH2Cl2 to within the range from 1:0.05 to 1:0.5, initially maintaining a reduced throughput of 0.05 - 2.5 liters/h cm2 until the precipitated layer of silicon has reached a thickness of about 2 or 5 microns, and thereafter applying a throughput of about 5 liters/h cm2.
Claim 6
Dependent Claim
22 words
The method as claimed in claim 1, wherein hydrogen halide and H2 and a gaseous halogen or hydride of silicon are admixed.
Claim 7
Dependent Claim
22 words
The method as claimed in claim 1, wherein hydrogen chloride and H2 and a gaseous halogen or hydride of silicon are admixed.
Claim 8
Dependent Claim
23 words
The method as claimed in claim 1, wherein an inert gas and H2 and a gaseous halogen or hydride of silicon are admixed.
Claim 9
Dependent Claim
13 words
The method as claimed in claim 1, wherein the silicon hydride is SiH4.
Claim 10
Dependent Claim
75 words
The method as claimed in claim 2, wherein the gaseous halide is SiHCl3, and further comprising setting at a reaction temperature of about 1,200*C the molar ratio of hydrogen to SiHCl3 to within the range from 1:0.02 to 1:0.2, initially maintaining a reduced throughput of 0.05 - 2.5 liters/h cm2 until the precipitated layer of silicon reaches a thickness of about 2 or 5 microns, and thereafter applying a throughput of about 5 liters/h cm2.
Claim 11
Dependent Claim
18 words
The method as claimed in claim 3, wherein the molar ratio of H2 to SiCl4 is about 1:0.01.
Claim 12
Dependent Claim
18 words
The method as claimed in claim 4, wherein the molar ratio of H2 to SiH2Cl2 is about 1:0.15.
Claim 13
Dependent Claim
14 words
The method as claimed in claim 8, wherein the gases are SiH4 and HCl.
Claim 14
Dependent Claim
16 words
The method as claimed in claim 9, wherein the molar ratio of H2:SiHCl3 is about 1:0.08.
References Cited (Backward Citations)
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US3484311A
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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) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |