US3901182A Expired / Lapsed US ⏱️ 0.0 years remaining

Silicon source feed process

Assignee: Harris Corp

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Filing: 1972-05-18

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Granted: 1975-08-26

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Expires: 1992-05-18

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Abstract

Abstract A process is disclosed for chemical vapor deposition (CVD) of silicon onto a substrate. In the process hydrogen gas is bubbled through a suitable liquid source of silicon, such as SiCl4 or SiHCl3, to evaporate liquid therefrom and to carry the vapor in a gas stream. A constant temperature reflex condenser is used to control the concentration of the gas stream. The said bubbler is maintained at room temperature and the said condenser is maintained at a temperature which is the lowest in the entire CVD system, and below the lowest possible temperature of the liquid source attributable to heat loss through vaporization. The effluent gas stream of the condenser is at a substantially constant temperature, and the concentration of vapor in the gas stream is thus held substantially constant through the deposition process of the silicon onto the substrate.

Inventors

👤 Ping-Wang Chiang

Bibliographic Details

Application Number —

Jurisdiction US

Data Source google_patents

Last Synchronized 2026-10-31 12:22

CPC Classifications

C; C23; C23C; C23C16/00; C23C16/44; C23C16/448; C23C16/4487; C23C16/22; C23C16/24; C23C16/4481; C23C16/4482; C30; C30B; C30B25/00; C30B25/02; C30B29/00; C30B29/02; C30B29/06; Y; Y10; Y10S; Y10S118/00; Y10S118/90; Y10T; Y10T137/00; Y10T137/6416; Y10T137/6579

Claims Analysis

Total Claims: 16

Claim 1

Independent Claim 127 words

A CHEMICAL VAPOR DEPOSITION FEED SYSTEM FOR DEPOSITION OF MATERIAL FROM A VAPOR UNTO A SUBSTRATE, SAID SYSTEM COMPRISING, A LIQUID SOURCE OF THE MATERIAL TO BE DEPOSITED, MEANS FOR PASSING A CARRIER GAS THROUGH SAID LIQUID SOURCE TO EVAPORATE LIQUID THEREFROM, CONDUIT MEANS FOR RECIEVING THE VAPORCARRYING GAS STREAM ISSUING FROM SAID LIQUID SOURCE, AND HEAT EXCHANGE CONNECTED TO SAID CONDUIT MEANS DOWNSTREAM OF SAID LIQUID SOURCE FOR CONDENSING A PORTION OF THE VAPOR IN THE GAS STREAM AND RETURNING THE CONDENSED VAPOR TO SAID LIQUID SOURCE TO MAINTAIN THE EFFLUENT VAPOR-CARRYING GAS STREAM FROM SAID HEAT EXCHANGE MEANS AT A SUBSTANTIALLY CONSTANT TEMPERATURE WHEREBY THE VAPOR CONCENTRATION OF SOURCE MATERIAL IN SAID GAS STREAM REMAINS SUBSTANTIALLY CONSTANT THROUGHOUT DEPOSITION OF SAID MATERIAL ONTO A SUBSTRATE.

Claim 2

Dependent Claim 127 words

Claim 3

Dependent Claim 34 words

The system according to claim 1, wherein said condensed portion of the vapor is the excess over that necessary to maintain the effluent gas stream of the heat exchange means saturated with said vapor.

Claim 4

Dependent Claim 18 words

The system according to claim 1, wherein said liquid is confined in a container maintained at room temperature.

Claim 5

Dependent Claim 47 words

The system according to claim 3, wherein is included means for maintaining said heat exchange means at a constant temperature which is the lowest in the entire chemical vapor deposition system and below the lowest possible temperature of said liquid source attributable to heat loss from vaporization.

Claim 6

Dependent Claim 53 words

The system according to claim 1, wherein is provided means for cooling said heat exchange means to a constant temperature below the temperature of said liquid source, to maintain the temperature of said effluent gas stream of said heat exchange means within approximately 0.5*C of said constant temperature of the heat exchange means.

Claim 7

Dependent Claim 13 words

The system according to claim 1, wherein the deposited material is a semiconductor.

Claim 8

Dependent Claim 12 words

The system according to claim 6, wherein said semiconductor is substantially pure.

Claim 9

Dependent Claim 41 words

The system according to claim 6, wherein is included means for introducing a dopant gas stream into the gas stream containing said vapor in the vicinity of said substrate, to provide a predetermined impurity concentration in the otherwise pure deposited semiconductor.

Claim 10

Dependent Claim 12 words

The system according to claim 1, wherein said substrate comprises a semiconductor.

Claim 11

Dependent Claim 13 words

The system according to claim 1, wherein said substrate is a single crystal.

Claim 12

Dependent Claim 13 words

The system according to claim 1, wherein said substrate is a refractory material.

Claim 13

Dependent Claim 13 words

The system according to claim 1, wherein said substrate is an amorphous film.

Claim 14

Dependent Claim 30 words

The system according to claim 1, wherein said material to be deposited is silicon, and said liquid source is a composition selected from the group consisting of SiCl4 and SiHCl3.

Claim 15

Dependent Claim 12 words

The system according to claim 13, wherein said carrier gas is hydrogen.

Claim 16

Dependent Claim 28 words

The system according to claim 4, wherein said heat exchange means is disposed above said liquid source to return the condensed vapor to said liquid source by gravity.

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)	1978-08-25	1979-02-24	1979-08-26	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-08-25	1983-02-24	1983-08-26	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-08-25	1987-02-24	1987-08-26	$7700.00	Window Closed / Lapsed

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