US5268989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi zone illuminator with embeded process control sensors and light interference elimination circuit
Assignee: Texas Instruments Inc
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Filing: 1992-04-16
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Granted: 1993-12-07
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Expires: 2012-04-16
Abstract
Abstract A multi-zone illuminator for processing semiconductor wafers comprises a plurality of source lamps and dummy lamps embedded in the reflector side of a lamp housing. The source lamps are arranged in a plurality of concentric circular zones. The illuminator also comprises plurality of light pipes for receiving multi-point temperature sensors to measure the semiconductor wafer temperature and its distribution uniformity. A gold-plated reflector plate is attached to the bottom side of the lamp housing for reflecting and directing optical energy toward the wafer surface. The distance between the reflector plate and the wafer and the lamps and the wafer may be adjusted with the use of a spacial elevator and adaptor assembly. The multi-zone illuminator allows uniform wafer heating during both transient and steady-state wafer heating cycles.
Inventors
- 👤 Mehrdad M. Moslehi
- 👤 Robert Matthews
- 👤 Cecil J. Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:25
CPC Classifications
H; H10; H10P; H10P34/00; H10P72/00; H10P72/04; H10P72/0431; H10P72/0436
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
102 words
A multi-zone illuminator for processing semiconductor wafers comprising: a. a lamp housing having a bottom side; b. a plurality of point source lamps embedded in said bottom side, said lamps arranged in a plurality of concentric circular zones for generating and directing optical energy; c. a reflector plate attached to said bottom side for reflecting and directing optical energy; and d. a light interference elimination circuit (LIEC) including at least one dummy lamp embedded in said bottom side for measuring light modulation depth, wherein at least one dummy lamp is associated with at least one of said plurality of concentric circular zones.
Claim 2
Dependent Claim
102 words
A multi-zone illuminator for processing semiconductor wafers comprising: a. a lamp housing having a bottom side; b. a plurality of point source lamps embedded in said bottom side, said lamps arranged in a plurality of concentric circular zones for generating and directing optical energy; c. a reflector plate attached to said bottom side for reflecting and directing optical energy; and d. a light interference elimination circuit (LIEC) including at least one dummy lamp embedded in said bottom side for measuring light modulation depth, wherein at least one dummy lamp is associated with at least one of said plurality of concentric circular zones.
Claim 3
Dependent Claim
35 words
The apparatus of claim 1 further comprising: a. a plurality of light pipes embedded in said bottom side; and b. a light pipe located in at least one of said dummy lamps for each zone.
Claim 4
Dependent Claim
130 words
The apparatus of claim 2, wherein said light interference elimination circuit comprises: a plurality of wafer temperature sensors insertable in said plurality of light pipes embedded in said bottom side; b. a plurality of lamp radiance sensors insertable in said light pipes located in said dummy lamps; c. a modulation source for modulating said heating lamps and dummy lamps to a selected modulation depth and frequency; d. circuitry to determine the magnitude of the modulation depth of the radiation detected in at least one of said plurality of lamp radiance sensors; e. circuitry to determine the magnitude of the lamp interference signals embedded in said plurality of wafer temperature sensors; and f. circuitry to subtract said lamp interference signals from said wafer temperature sensor signals to determine the wafer temperature.
Claim 5
Dependent Claim
38 words
The apparatus of claim 1, wherein said source lamps are associated within each of said circular zones to provide an approximately continuous ring of said optical energy from each of said circular zones at the semiconductor wafer surface.
Claim 6
Dependent Claim
23 words
The apparatus of claim 1, wherein said illuminator comprises a plurality of cooling channels for flowing a cooling fluid to cool said reflector.
Claim 7
Dependent Claim
29 words
The apparatus of claim 1, further comprising a plurality of adjustable power supplies, each of said adjustable power supplies associated to provide electrical power to a respective lamp zone.
Claim 8
Dependent Claim
18 words
The apparatus of claim 6 wherein each power supply also provides power to at least one dummy lamp.
Claim 9
Dependent Claim
12 words
The apparatus of claim 1, wherein said source lamps comprise tungsten-halogen lamps.
Claim 10
Dependent Claim
19 words
The apparatus of claim 1, wherein each of said source lamps comprise a 500 to 2000 watt tungsten-halogen lamp.
Claim 11
Dependent Claim
19 words
The apparatus of claim 1 further including a means for adjusting the spacing between said lamps and said wafer.
Claim 12
Dependent Claim
47 words
The apparatus of claim 10 wherein said means for adjusting is also capable of adjusting the spacing between said reflector plate and said wafer wherein the spacing between the lamps and the wafer may be adjusted independently of the spacing between the reflector plate and the wafer.
Claim 13
Dependent Claim
14 words
The apparatus of claim 1 wherein said reflector plate is flat and gold plated.
Claim 14
Dependent Claim
172 words
A multi-zone illuminator for processing semiconductor wafers comprising: a. a lamp housing having a bottom side; b. a plurality of source lamps embedded in said bottom side, said lamps arranged in a four concentric circular zones wherein each zone provides a nearly continuous ring of optical energy for uniform wafer heating; c. a plurality of adjustable power supplies, each of said adjustable power supplies associated to provide electrical power to a respective concentric circular zone; d. a plurality of dummy lamps embedded in said bottom side for measuring light modulation depth, wherein at least one dummy lamp is powered by each power supply and includes a light pipe for receiving one of a plurality of first fiber-optic radiance sensors; e. a plurality of light pipes embedded in said bottom side for receiving a plurality of second fiber-optic wafer temperature sensors; f. a flat gold-plated reflector plate attached to said bottom side for reflecting and directing optical energy; and g. a means for adjusting the lamp-to-wafer spacing and the reflector to wafer spacing.
Claim 15
Dependent Claim
172 words
A multi-zone illuminator for processing semiconductor wafers comprising: a. a lamp housing having a bottom side; b. a plurality of source lamps embedded in said bottom side, said lamps arranged in a four concentric circular zones wherein each zone provides a nearly continuous ring of optical energy for uniform wafer heating; c. a plurality of adjustable power supplies, each of said adjustable power supplies associated to provide electrical power to a respective concentric circular zone; d. a plurality of dummy lamps embedded in said bottom side for measuring light modulation depth, wherein at least one dummy lamp is powered by each power supply and includes a light pipe for receiving one of a plurality of first fiber-optic radiance sensors; e. a plurality of light pipes embedded in said bottom side for receiving a plurality of second fiber-optic wafer temperature sensors; f. a flat gold-plated reflector plate attached to said bottom side for reflecting and directing optical energy; and g. a means for adjusting the lamp-to-wafer spacing and the reflector to wafer spacing.
Claim 16
Dependent Claim
49 words
The apparatus of claim 13, wherein said four concentric lamp zones comprise an outer circular lamp zone having 29 point-source lamps, an outer middle circular lamp zone having 20 point-source lamps, an inner middle circular zone having 11 point-source lamps, and a center circular zone having five point-source lamps.
Claim 17
Dependent Claim
91 words
The apparatus of claim 13, further comprising: a. a modulation source for modulating said lamps and dummy lamps to a selected modulation depth and frequency; b. circuitry to determine the magnitude of the modulation depth of the radiation detected in at least one of said plurality of first fiber-optic sensors; c. circuitry to determine the magnitude of the lamp interference of signals embedded in said plurality of second fiber-optic sensors; and d. circuitry to subtract said lamp interference signals from said wafer temperature sensor signals to determine the true wafer temperature.
Claim 18
Dependent Claim
27 words
The apparatus of claim 13, wherein said housing comprises a plurality of cooling channels for flowing a cooling fluid to cool said reflector and said light pipes.
Claim 19
Dependent Claim
12 words
The apparatus of claim 13, wherein said source lamps comprises tungsten-halogen lamps.
Claim 20
Dependent Claim
19 words
The apparatus of claim 13, wherein each of said point-source lamps comprise a 500 to 2000 watt tungsten-halogen lamp.
Claim 21
Dependent Claim
49 words
The apparatus of claim 13, wherein said four concentric lamp zones comprise an outer circular lamp zone having 29 source lamps, an outer middle circular lamp zone having 20 source lamps, an inner middle circular zone having 11 source lamps, and a center circular zone having five source lamps.
Claim 22
Dependent Claim
180 words
A rapid thermal processor adapted to process a semiconductor wafer, said processor comprising: a. a quartz window above said wafer; and b. a multi-zone illuminator located above said quartz window comprising: i. a lamp housing having a bottom side; ii. a plurality of point source lamps embedded in said bottom side, said lamps arranged in four concentric circular zones wherein each zone provides a nearly continuous ring of optical energy for uniform wafer heating; iii. a plurality of adjustable power supplies, each of said adjustable power supplies associated to provide electrical power to a respective concentric circular zone; iv. a light interference elimination circuit (LIEC) including a plurality of dummy lamps embedded in said bottom side for measuring light modulation depth, wherein at least one dummy lamp is powered by each power supply and includes a light pipe for receiving one of a plurality of first fiber-optic sensors; v. a flat gold-plated reflector plate attached to said bottom side for reflecting and directing optical energy; and vi. a means for adjusting the lamp to wafer spacing and the reflector-to-wafer spacing.
Claim 23
Dependent Claim
180 words
A rapid thermal processor adapted to process a semiconductor wafer, said processor comprising: a. a quartz window above said wafer; and b. a multi-zone illuminator located above said quartz window comprising: i. a lamp housing having a bottom side; ii. a plurality of point source lamps embedded in said bottom side, said lamps arranged in four concentric circular zones wherein each zone provides a nearly continuous ring of optical energy for uniform wafer heating; iii. a plurality of adjustable power supplies, each of said adjustable power supplies associated to provide electrical power to a respective concentric circular zone; iv. a light interference elimination circuit (LIEC) including a plurality of dummy lamps embedded in said bottom side for measuring light modulation depth, wherein at least one dummy lamp is powered by each power supply and includes a light pipe for receiving one of a plurality of first fiber-optic sensors; v. a flat gold-plated reflector plate attached to said bottom side for reflecting and directing optical energy; and vi. a means for adjusting the lamp to wafer spacing and the reflector-to-wafer spacing.
References Cited (Backward Citations)
US4859832A
Cited
US4890245A
Cited
US4836138A
Cited
US4979133A
Cited
US4979134A
Cited
US4956538A
Cited
US4984902A
Cited
US5108792A
Cited
US5098198A
Cited
US5179677A
Cited
US5102231A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-12-06 | 1997-06-07 | 1997-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-12-06 | 2001-06-07 | 2001-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-12-06 | 2005-06-07 | 2005-12-07 | $7700.00 | Window Closed / Lapsed |