US5231690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wafer heaters for use in semiconductor-producing apparatus and heating units using such wafer heaters
Assignee: NGK Insulators Ltd
•
Filing: 1991-03-12
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Granted: 1993-07-27
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Expires: 2011-03-12
Abstract
Abstract A wafer heater for use in a semiconductor producing apparatus or the like. The heater includes a discoidal substrate made of a dense ceramic, and a resistance heating element buried in the substrate. The surface of the substrate other than that surface upon which a wafer is to be placed for heating is a flat surface. A heating unit is also disclosed, which includes such a heater in a chamber for the semiconductor-producing apparatus. The heating unit further involves a hollow sheath of which inner pressure is not substantially varied even when the pressure inside the chamber changes and is joined to the heater, and a thermocouple inserted into the hollow sheath. Further, a projecting support portion may be provided on the surface of the substrate other than that surface upon which the wafer is to be placed for heating, and lead wires connected to the resistance heating element, wherein when the heater is placed in the chamber, the projecting support portion forms a gas-tight seal between the chamber, and the lead wires are taken out from the chamber such that the lead wires may not substantially be exposed to an inner space inside the chamber.
Inventors
- 👤 Takao Soma
- 👤 Ryusuke Ushikoshi
- 👤 Kazuhiro Nobori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:50
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/04; H10P72/0431; H10P72/0432
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
70 words
A wafer heater for use in a gas-containing chamber of a semiconductor-producing apparatus, said heater comprising a discoidal substrate made of a substantially gas-tight, unitary sintered ceramic, and a resistance heating element buried in and integrally bonded to said substrate, wherein that surface of the substrate upon which a wafer is to be place is a flat surface, and said resistance heating element is sealed from communication with the gas.
Claim 2
Dependent Claim
70 words
A wafer heater for use in a gas-containing chamber of a semiconductor-producing apparatus, said heater comprising a discoidal substrate made of a substantially gas-tight, unitary sintered ceramic, and a resistance heating element buried in and integrally bonded to said substrate, wherein that surface of the substrate upon which a wafer is to be place is a flat surface, and said resistance heating element is sealed from communication with the gas.
Claim 3
Dependent Claim
41 words
The wafer heater according to claim 1, wherein a ceramic film is formed, by chemical vapor deposition or thermal chemical vapor deposition, on that surface of the substrate which is to contact the gas inside the chamber of said semiconductor-producing apparatus.
Claim 4
Dependent Claim
19 words
The wafer heater according to claim 2, wherein the substrate is composed mainly of Si 3 N 4 .
Claim 5
Dependent Claim
19 words
The wafer heater according to claim 1, wherein the substrate is composed mainly of Si 3 N 4 .
Claim 6
Dependent Claim
27 words
The wafer heater according to claim 1, wherein the resistance heating element is composed of a material selected from the group consisting of tungsten, molybdenum and platinum.
Claim 7
Dependent Claim
112 words
The heater according to claim 1, wherein the semiconductor-producing apparatus includes a vessel defining a chamber and said heater further comprises a projecting support portion provided on a surface of the substrate other than that surface upon which the wafer is to be placed for heating, and lead wires connected to the resistance heating element, wherein when the heater is placed in an opening of the vessel, the projecting support portion forms a gas-tight seal between the chamber and an exterior of the vessel, and the lead wires are taken out from the chamber such that at least the lead wires are not substantially exposed to an inner space of the chamber.
Claim 8
Dependent Claim
46 words
The heater according to claim 6, wherein one end of a thermocouple is buried in the substrate, and the other end is taken out from the chamber such that the lead wire of the thermocouple is not substantially exposed to an inner space of the chamber.
Claim 9
Dependent Claim
16 words
The heater according to claim 7, wherein said projecting support portion is composed of a ceramic.
Claim 10
Dependent Claim
46 words
The heater according to claim 7, wherein the projecting support portion is composed of a metal or a metal compound, and is bonded to that surface of the substrate which is other than the surface of the heater upon which the wafer is to be placed.
Claim 11
Dependent Claim
16 words
The heater according to claim 8, wherein said projecting support portion is composed of a ceramic.
Claim 12
Dependent Claim
46 words
The heater according to claim 8, wherein the projecting support portion is composed of a metal or a metal compound, and is bonded to that surface of the substrate which is other than the surface of the heater upon which the wafer is to be placed.
Claim 13
Dependent Claim
18 words
The heater according to claim 1, wherein said substrate has a wafer absorption of not more than 0.01%.
Claim 14
Dependent Claim
21 words
The heater according to claim 1, wherein the surface of said substrate has a flatness of not greater than 500 microns.
References Cited (Backward Citations)
US2961523A
Cited
US3220380A
Cited
US3187162A
Cited
US3381114A
Cited
US3391270A
Cited
US3386853A
Cited
US3465204A
Cited
US3505499A
Cited
US3894343A
Cited
US3786233A
Cited
US4032817A
Cited
US4169007A
Cited
GB2057761A
Cited
JPS60106968A
Cited
US4639712A
Cited
US4692420A
Cited
US4665627A
Cited
US4783908A
Cited
US4773167A
Cited
EP0267451A1
Cited
US4778559A
Cited
JPS63196033A
Cited
JPS63278322A
Cited
DE3914699A1
Cited
EP0376387A1
Cited
US5105066A
Cited
US5063031A
Cited
US5126533A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-07-26 | 1997-01-25 | 1997-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-26 | 2001-01-25 | 2001-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-26 | 2005-01-25 | 2005-07-27 | $7700.00 | Window Closed / Lapsed |