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US5294778A Expired / Lapsed US ⏱️ 0.0 years remaining

CVD platen heater system utilizing concentric electric heating elements

Assignee: Lam Research Corp
•
Filing: 1991-09-11
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Granted: 1994-03-15
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Expires: 2011-09-11
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Abstract

Abstract A wafer support platen heating system for low pressure chemical vapor deposition of apparatus includes multiple resistance heaters for individual heating of multiple portions of the platen to provide a predetermined uniform or non-uniform temperature gradient/profile across the platen. The multiple graphite resistance heaters of the preferred embodiment include a spiral shaped main resistance heater and two single turn edge loss graphite resistance heaters located within the inner diameter and along the periphery of the outer diameter respectively of the main spiral shaped resistance heater.

Inventors

  • 👤 Justice Carman
  • 👤 Mark A. Logan
  • 👤 Joseph Monkowski

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 12:07
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/04; H10P72/0431; H10P72/0432; C; C23; C23C; C23C16/00; C23C16/44; C23C16/458; C23C16/4582; C23C16/4583; C23C16/4586

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 249 words
A heating system for heating a chemical vapor deposition reaction chamber support platen, comprising: a) first and second heating means for heating first and second portions of said platen; b) first and second temperature sensing means for sensing the temperature of said first and second portions of said platen respectively; c) first and second power control means responsive respectively to said first and second temperature sensing means for varying the power input to said first and second heating means to provide individual temperature control of said first and second portions of said platen; d) a third heating means for heating a third portion of the platen; e) a third temperature sensing means for sensing the temperature of said third portion of the platen; and f) a third power control means for varying the power input to said third heating means to provide individual temperature control of said third portion of the platen; wherein the first heating means has a spiral shape defining both an inner diameter and an outer diameter, the second heating means has a single turn circular shape and the third heating means has a single turn circular shape, the second heating means has a diameter less than the inner diameter of the first heating means and is located within the inner diameter of the first heating means, the third heating means as a diameter greater than the outer diameter of the first heating means and is located outside the outer diameter of the first heating means.
Claim 2
Dependent Claim 249 words
A heating system for heating a chemical vapor deposition reaction chamber support platen, comprising: a) first and second heating means for heating first and second portions of said platen; b) first and second temperature sensing means for sensing the temperature of said first and second portions of said platen respectively; c) first and second power control means responsive respectively to said first and second temperature sensing means for varying the power input to said first and second heating means to provide individual temperature control of said first and second portions of said platen; d) a third heating means for heating a third portion of the platen; e) a third temperature sensing means for sensing the temperature of said third portion of the platen; and f) a third power control means for varying the power input to said third heating means to provide individual temperature control of said third portion of the platen; wherein the first heating means has a spiral shape defining both an inner diameter and an outer diameter, the second heating means has a single turn circular shape and the third heating means has a single turn circular shape, the second heating means has a diameter less than the inner diameter of the first heating means and is located within the inner diameter of the first heating means, the third heating means as a diameter greater than the outer diameter of the first heating means and is located outside the outer diameter of the first heating means.
Claim 3
Dependent Claim 18 words
The platen heating system of claim 1 wherein the first, second and third heating means are resistance heaters.
Claim 4
Dependent Claim 24 words
The platen heating system of claim 2 wherein the first, second and third resistance heaters are made of graphite and coated with silicon carbide.
Claim 5
Dependent Claim 33 words
The platen heating system of claim 2 wherein the first, second and third resistance heaters are made of one of the materials from the group nickel chromium, tungsten or other standard resistance wire.
Claim 6
Dependent Claim 31 words
The platen heating system of claim 2 wherein the third graphite resistance heater has portions missing along its length to provide a convoluted path and thereby increased resistance to current flow.
Claim 7
Dependent Claim 25 words
The platen heating system of claim 2 wherein the third graphite resistance heater is made of wire wound in a spiral to provide increased resistance.
Claim 8
Dependent Claim 42 words
The platen heating system of claim 5 wherein the third graphite resistance heater has a cylindrical shape having both a top and bottom surface and wherein the missing portions are slits disposed along the top and bottom surfaces to a predetermined depth.
Claim 9
Dependent Claim 34 words
The platen heating system of claim 5 wherein the second graphite resistance heater has portions removed along its length to provide a convoluted path for current flow and increased resistance to reduce current flow.
Claim 10
Dependent Claim 58 words
The platen heating system of claim 8 wherein the second graphite resistance heater has a cylindrical shape having a top and bottom surface and inner and outer sidewall surfaces and wherein the removed portions ar slits disposed along either the top or bottom surface at predetermined locations and to predetermined depths along the inner and outer sidewall surfaces.

References Cited (Backward Citations)

US1975410A Cited
US2093939A Cited
US2330867A Cited
US3381114A Cited
JPS5944819A Cited
US4511789A Cited
JPS61142743A Cited
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JPS63196033A Cited
JPH0227715A Cited
JPH0380530A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-03-14 1997-09-13 1998-03-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-03-14 2001-09-13 2002-03-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-03-14 2005-09-13 2006-03-15 $7700.00 Window Closed / Lapsed

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