US5830277A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal processing system with supplemental resistive heater and shielded optical pyrometry
Assignee: Mattson Technology Inc
•
Filing: 1995-05-26
•
Granted: 1998-11-03
•
Expires: 2015-05-26
Abstract
Abstract System and method for determining thermal characteristics, such as temperature, temperature uniformity and emissivity, during thermal processing using shielded pyrometry. The surface of a semiconductor substrate is shielded to prevent interference from extrinsic light from radiant heating sources and to form an effective black-body cavity. An optical sensor is positioned to sense emitted light in the cavity for pyrometry. The effective emissivity of the cavity approaches unity independent of the semiconductor substrate material which simplifies temperature calculation. The shield may be used to prevent undesired backside deposition. Multiple sensors may be used to detect temperature differences across the substrate and in response heaters may be adjusted to enhance temperature uniformity.
Inventors
- 👤 Kristian E. Johnsgard
- 👤 James McDiarmid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:22
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/06; H10P72/0602; C; C23; C23C; C23C16/00; C23C16/44; C23C16/48; C23C16/481; G; G01; G01J; G01J5/00; G01J5/0003; H10P72/04; H10P72/0431; H10P72/0436
Claims Analysis
Total Claims: 85
Claim 1
Independent Claim
138 words
A thermal processing system for processing a semiconductor substrate at a processing temperature comprising: a processing chamber within which the substrate is placed for processing; at least one heater for providing heat to the processing chamber; a shield comprising a material substantially nontransmissive to light within a given range of wavelengths at the processing temperature; the shield forming a cavity adjacent to the substrate wherein extrinsic light within the given range of wavelengths is prevented from reflecting into the cavity; the shield absorbing heat and emitting substantial thermal radiation within the cavity; wherein the shield provides thermal insulation for maintaining substantial temperature uniformity of the substrate during processing; and a first optical sensor disposed for sampling the intensity of light in the cavity within the given range of wavelengths and for producing an output representative of said intensity.
Claim 2
Dependent Claim
138 words
A thermal processing system for processing a semiconductor substrate at a processing temperature comprising: a processing chamber within which the substrate is placed for processing; at least one heater for providing heat to the processing chamber; a shield comprising a material substantially nontransmissive to light within a given range of wavelengths at the processing temperature; the shield forming a cavity adjacent to the substrate wherein extrinsic light within the given range of wavelengths is prevented from reflecting into the cavity; the shield absorbing heat and emitting substantial thermal radiation within the cavity; wherein the shield provides thermal insulation for maintaining substantial temperature uniformity of the substrate during processing; and a first optical sensor disposed for sampling the intensity of light in the cavity within the given range of wavelengths and for producing an output representative of said intensity.
Claim 3
Dependent Claim
28 words
The system of claim 1, wherein the shield forms an aperture and the first optical sensor samples the intensity of the light in the cavity through the aperture.
Claim 4
Dependent Claim
30 words
The system of claim 2, wherein the optical sensor passes through the aperture such that the optical sensor is directly exposed to light emitted from the substrate within the cavity.
Claim 5
Dependent Claim
33 words
The system of claim 3, further comprising a processing chamber containing a substance for forming deposits on the substrate; wherein the shield substantially prevents the substance from forming deposits on the optical sensor.
Claim 6
Dependent Claim
36 words
The system of claim 2, wherein the aperture and the cavity each have a surface area, and the surface area of the aperture is less than one tenth (0.1) of the surface area of the cavity.
Claim 7
Dependent Claim
45 words
The system of claim 2, wherein: the shield comprises at least two pieces, including a rotating piece and a non-rotating piece; the rotating piece supports the substrate and rotates the substrate during processing; and the non-rotating piece forms the aperture for the first optical sensor.
Claim 8
Dependent Claim
63 words
The system of claim 1 further comprising a processing chamber containing a substance for forming a deposit on the substrate; wherein a first surface of the substrate is exposed to the processing chamber and a second surface of the substrate is exposed to the cavity; and the shield substantially prevents the substance from forming a deposit on the second surface of the substrate.
Claim 9
Dependent Claim
23 words
The system of claim 1, wherein the substrate is substantially nontransmissive to light within the given range of wavelengths at the processing temperature.
Claim 10
Dependent Claim
20 words
The system of claim 1, wherein the given range of wavelengths is less than three and one half (3.5) micrometers.
Claim 11
Dependent Claim
27 words
The system of claim 1, wherein the given range of wavelengths is within the range of about eight tenths (0.8) to one and two tenths (1.2) micrometers.
Claim 12
Dependent Claim
13 words
The system of claim 1, wherein the optical sensor comprises an optically-transmissive fiber.
Claim 13
Dependent Claim
14 words
The system of claim 1, wherein the optical sensor comprises an optically-transmissive light pipe.
Claim 14
Dependent Claim
47 words
The system of claim 1, wherein the cavity has an effective emissivity at the processing temperature, the substrate has an intrinsic emissivity at the processing temperature, and the effective emissivity of the cavity is substantially greater than the intrinsic emissivity of the substrate at the processing temperature.
Claim 15
Dependent Claim
11 words
The system of claim 1, wherein the shield comprises silicon carbide.
Claim 16
Dependent Claim
10 words
The system of claim 1, wherein the shield comprises graphite.
Claim 17
Dependent Claim
13 words
The system of claim 1, wherein the shield comprises silicon carbide coated graphite.
Claim 18
Dependent Claim
11 words
The system of claim 1, wherein the shield comprises polycrystalline silicon.
Claim 19
Dependent Claim
29 words
The system of claim 1, wherein the thermal insulation provided by the shield varies across the substrate such that the uniformity of the substrate's temperature is enhanced during processing.
Claim 20
Dependent Claim
30 words
The system of claim 1, wherein the shield provides a greater amount of thermal insulation at a peripheral region of the substrate than in a central region of the substrate.
Claim 21
Dependent Claim
25 words
The system of claim 1, wherein the shield has a thickness selected such that the shield and the substrate heat at substantially the same rate.
Claim 22
Dependent Claim
34 words
The system of claim 1, wherein the shield and the substrate each have a thickness, and the thickness of the shield is within a factor of three (3) of the thickness of the substrate.
Claim 23
Dependent Claim
15 words
The system of claim 1, wherein the surface of the shield is coated with silicon.
Claim 24
Dependent Claim
42 words
The system of claim 1, wherein the heater comprises a radiant energy heating source which radiates light to heat the substrate, wherein the light radiated by the radiant energy heating source includes light with substantial intensity within the given range of wavelengths.
Claim 25
Dependent Claim
20 words
The system of claim 1, further comprising a second heater providing heat predominantly at a peripheral region of the substrate.
Claim 26
Dependent Claim
22 words
The system of claim 24, wherein the second heater is a resistive heater positioned adjacent to a peripheral region of the substrate.
Claim 27
Dependent Claim
43 words
The system of claim 1, further comprising an optical pyrometer responsive to the output of the optical sensor for determining the temperature of the substrate as a function of the optical sensor output and for producing a control signal representative of said temperature.
Claim 28
Dependent Claim
41 words
The system of claim 26, further comprising a heater control for controlling the heater; the heater control adjusting the heat provided by the heater to compensate for the detected temperature difference in response to the control signal from the optical pyrometer.
Claim 29
Dependent Claim
25 words
The system of claim 27, further comprising a resistive second heater responsive to the heater control positioned adjacent to a peripheral region of the substrate.
Claim 30
Dependent Claim
20 words
A The system of claim 1, wherein the shield comprises at least two pieces separated by at least one channel.
Claim 31
Dependent Claim
19 words
The system of claim 1, wherein the processing temperature is greater than about six hundred degrees Celsius (600° C.).
Claim 32
Dependent Claim
17 words
The system of claim 1, further comprising an inlet for providing a purge gas to the cavity.
Claim 33
Dependent Claim
32 words
The system of claim 1 further comprising a sheath for the first optical sensor, wherein the sheath forms a path for providing a purge gas to inhibit deposits on the optical sensor.
Claim 34
Dependent Claim
16 words
The system of claim 1, wherein the surface of the shield is more emissive than reflective.
Claim 35
Dependent Claim
25 words
The system of claim 1, wherein the surface of the shield reaches a temperature greater than about six hundred degrees Celsius (600° C.) during processing.
Claim 36
Dependent Claim
16 words
The system of claim 34, wherein the surface of the shield is more emissive than reflective.
Claim 37
Dependent Claim
22 words
The system of claim 1, further comprising a resistive peripheral heater with a high thermal mass heating element adjacent to the substrate.
Claim 38
Dependent Claim
13 words
The system of claim 36 wherein the peripheral heater is a ring heater.
Claim 39
Dependent Claim
32 words
The system of claim 1, further comprising a supplementary resistive heater adjacent to the shield, wherein the supplementary resistive heater heats the shield to enhance the thermal insulation provided for the substrate.
Claim 40
Dependent Claim
228 words
A thermal processing system for processing a semiconductor substrate within a range of processing temperatures, the processing system including an improved temperature control system for determining thermal characteristics of the substrate based upon light intensity within a given range of wavelengths, the temperature control system comprising: a shield comprising a material substantially nontransmissive to light within the given range of wavelengths at the processing temperatures; the shield having a surface positioned relative to the substrate such that a cavity is formed between the substrate and the surface of the shield; the shield and the substrate substantially preventing extrinsic light within the given range of wavelengths from reflecting into the cavity; a first optical sensor disposed for sampling the intensity of light in the cavity within the given range of wavelengths and for producing an output representative of said intensity; wherein the shield forms an aperture and the first optical sensor samples the intensity of the light in the cavity through the aperture; the shield comprises at least two pieces, including a rotating piece and a non-rotating piece; the rotating piece supports the substrate and rotates the substrate during processing; and the non-rotating piece forms the aperture for the first optical sensor; further comprising an elevational actuator coupled to the non-rotating piece such that raising and lowering the elevational actuator causes the non-rotating piece to be raised and lowered.
Claim 41
Dependent Claim
228 words
A thermal processing system for processing a semiconductor substrate within a range of processing temperatures, the processing system including an improved temperature control system for determining thermal characteristics of the substrate based upon light intensity within a given range of wavelengths, the temperature control system comprising: a shield comprising a material substantially nontransmissive to light within the given range of wavelengths at the processing temperatures; the shield having a surface positioned relative to the substrate such that a cavity is formed between the substrate and the surface of the shield; the shield and the substrate substantially preventing extrinsic light within the given range of wavelengths from reflecting into the cavity; a first optical sensor disposed for sampling the intensity of light in the cavity within the given range of wavelengths and for producing an output representative of said intensity; wherein the shield forms an aperture and the first optical sensor samples the intensity of the light in the cavity through the aperture; the shield comprises at least two pieces, including a rotating piece and a non-rotating piece; the rotating piece supports the substrate and rotates the substrate during processing; and the non-rotating piece forms the aperture for the first optical sensor; further comprising an elevational actuator coupled to the non-rotating piece such that raising and lowering the elevational actuator causes the non-rotating piece to be raised and lowered.
Claim 42
Dependent Claim
149 words
A thermal processing system for processing a semiconductor substrate comprising: a processing chamber wherein light is radiated into the processing chamber; a first surface of the substrate exposed to the processing chamber for processing; a shield having an interior surface positioned relative to a second surface of the substrate such that a shielded region is formed between the second surface of the substrate and the interior surface of the shield; the shield absorbing heat and emitting substantial thermal radiation within the shielded region; wherein the shield provides thermal insulation for maintaining substantial temperature uniformity of the substrate during processing; and an optical sensor disposed to sample the intensity of light emitted in the shielded region within a given range of wavelengths; wherein the shield and the substrate substantially prevent the light in the processing chamber from interfering with the intensity of the emitted light sampled by the optical sensor.
Claim 43
Dependent Claim
149 words
A thermal processing system for processing a semiconductor substrate comprising: a processing chamber wherein light is radiated into the processing chamber; a first surface of the substrate exposed to the processing chamber for processing; a shield having an interior surface positioned relative to a second surface of the substrate such that a shielded region is formed between the second surface of the substrate and the interior surface of the shield; the shield absorbing heat and emitting substantial thermal radiation within the shielded region; wherein the shield provides thermal insulation for maintaining substantial temperature uniformity of the substrate during processing; and an optical sensor disposed to sample the intensity of light emitted in the shielded region within a given range of wavelengths; wherein the shield and the substrate substantially prevent the light in the processing chamber from interfering with the intensity of the emitted light sampled by the optical sensor.
Claim 44
Dependent Claim
20 words
The system of claim 40, wherein the given range of wavelengths is greater than one and one half (1.5) micrometers.
Claim 45
Dependent Claim
38 words
The system of claim 40, further comprising a heater which radiates light into the processing chamber to heat the substrate wherein the light radiated by the heater includes light with substantial intensity within the given range of wavelengths.
Claim 46
Dependent Claim
20 words
The system of claim 42, wherein the given range of wavelengths is less than three and one half (3.5) micrometers.
Claim 47
Dependent Claim
27 words
The system of claim 42, wherein the given range of wavelengths is within the range of about eight tenths (0.8) to one and two tenths (1.2) micrometers.
Claim 48
Dependent Claim
21 words
The system of claim 44, wherein the heater is selected from the group consisting of tungsten filament lamps and arc lamps.
Claim 49
Dependent Claim
53 words
The system of claim 42, wherein the shield and the substrate are each substantially nontransmissive to light within the given range of wavelengths at a desired processing temperature, and the shield and the substrate substantially prevent light within the given range of wavelengths from reflecting into the shielded region from the processing chamber.
Claim 50
Dependent Claim
64 words
The system of claim 46, further comprising an optical pyrometer wherein: the shield forms an aperture and the optical sensor passes through the aperture such that the optical sensor is directly exposed to light emitted from the second surface of the substrate within the given range of wavelengths; and the optical sensor forms an optically-transmissive path from the shielded region to the optical pyrometer.
Claim 51
Dependent Claim
60 words
The system of claim 40 further comprising: a chamber wall forming an inlet for providing a substance into the processing chamber; wherein the substance comprises a material that forms a deposit on the first surface of the substrate at a processing temperature, and the shield substantially prevents the substance from forming a deposit on the second surface of the substrate.
Claim 52
Dependent Claim
16 words
The system of claim 48, wherein the shield substantially encloses a backside surface of the substrate.
Claim 53
Dependent Claim
39 words
The reactor of claim 48, wherein the shield forms at least one channel between the processing chamber and the shielded region and the channel is sufficiently narrow such that the substance is substantially prevented from entering the shielded region.
Claim 54
Dependent Claim
21 words
The system of claim 40, wherein the shield forms at least one channel between the processing chamber and the shielded region.
Claim 55
Dependent Claim
35 words
The system of claim 51, wherein the channel has a plurality of turns such that light within the given range of wavelengths is substantially prevented from reflecting into the shielded region from the processing chamber.
Claim 56
Dependent Claim
52 words
The system of claim 40, wherein the shielded region has an effective emissivity at a desired processing temperature, the substrate has an intrinsic emissivity at the desired processing temperature, and the effective emissivity of the shielded region is substantially greater than the intrinsic emissivity of the substrate at the desired processing temperature.
Claim 57
Dependent Claim
24 words
The system of claim 40, wherein the shield is substantially nontransmissive to light within the given range of wavelengths at a desired processing temperature.
Claim 58
Dependent Claim
26 words
The system of claim 40, wherein the interior surface of the shield reaches a temperature greater than about six hundred degrees Celsius (600° C.) during processing.
Claim 59
Dependent Claim
17 words
The system of claim 40, wherein the interior surface of the shield is more emissive than reflective.
Claim 60
Dependent Claim
92 words
A thermal processing system for processing a semiconductor substrate at a processing temperature comprising: a processing chamber; a thermally conducive support for the semiconductor substrate in the processing chamber, the support providing thermal insulation for the substrate; a lamp system for providing radiant energy to the substrate in the processing chamber; and a resistive peripheral heater adjacent to the support; wherein the peripheral heater heats the support to enhance the thermal insulation provided by the support at the periphery of the substrate for maintaining substantial temperature uniformity of the substrate during processing.
Claim 61
Dependent Claim
92 words
A thermal processing system for processing a semiconductor substrate at a processing temperature comprising: a processing chamber; a thermally conducive support for the semiconductor substrate in the processing chamber, the support providing thermal insulation for the substrate; a lamp system for providing radiant energy to the substrate in the processing chamber; and a resistive peripheral heater adjacent to the support; wherein the peripheral heater heats the support to enhance the thermal insulation provided by the support at the periphery of the substrate for maintaining substantial temperature uniformity of the substrate during processing.
Claim 62
Dependent Claim
16 words
The system of claim 57, wherein the support forms a heated cavity adjacent to the substrate.
Claim 63
Dependent Claim
16 words
The system of claim 58, wherein the substrate forms one of the walls of the cavity.
Claim 64
Dependent Claim
19 words
The system of claim 58, wherein the support forms a wall of the cavity substantially parallel to the substrate.
Claim 65
Dependent Claim
20 words
The system of claim 58 further comprising an optical sensor for sampling the intensity of radiant energy in the cavity.
Claim 66
Dependent Claim
23 words
The system of claim 58, wherein the support has a thickness within a factor of three (3) of the thickness of the substrate.
Claim 67
Dependent Claim
19 words
The system of claim 58, wherein the processing temperature is greater than about six hundred degrees Celsius (600° C.).
Claim 68
Dependent Claim
27 words
The system of claim 57, wherein the heating element of the peripheral heater has a substantially higher thermal mass then the heating element of the lamp system.
Claim 69
Dependent Claim
25 words
The system of claim 57, wherein the support has a thickness selected such that the support and the substrate heat at substantially the same rate.
Claim 70
Dependent Claim
23 words
The system of claim 57, wherein the support has a thickness within a factor of three (3) of the thickness of the substrate.
Claim 71
Dependent Claim
18 words
The system of claim 57, wherein the support rotates the substrate relative to the peripheral heater during processing.
Claim 72
Dependent Claim
19 words
The system of claim 57, wherein the processing temperature is greater than about six hundred degrees Celsius (600° C.).
Claim 73
Dependent Claim
14 words
The system of claim 57 wherein the peripheral heater comprises silicon carbide coated graphite.
Claim 74
Dependent Claim
11 words
The system of claim 57 wherein the support comprises silicon carbide.
Claim 75
Dependent Claim
88 words
A thermal processing system for processing a semiconductor substrate at a processing temperature comprising: a processing chamber within which the substrate is placed for processing; a lamp system for providing radiant energy to the processing chamber; a radiation shield forming a cavity adjacent to the substrate, the shield absorbing heat and emitting substantial thermal radiation within the cavity; and a supplemental resistive heater to heat the shield; wherein the supplemental resistive heater and the shield provide thermal insulation for maintaining substantial temperature uniformity of the substrate during processing.
Claim 76
Dependent Claim
88 words
A thermal processing system for processing a semiconductor substrate at a processing temperature comprising: a processing chamber within which the substrate is placed for processing; a lamp system for providing radiant energy to the processing chamber; a radiation shield forming a cavity adjacent to the substrate, the shield absorbing heat and emitting substantial thermal radiation within the cavity; and a supplemental resistive heater to heat the shield; wherein the supplemental resistive heater and the shield provide thermal insulation for maintaining substantial temperature uniformity of the substrate during processing.
Claim 77
Dependent Claim
16 words
The system of claim 71, wherein the substrate forms one of the walls of the cavity.
Claim 78
Dependent Claim
19 words
The system of claim 71, wherein the supplemental heater provides heat preferentially to the peripheral region of the substrate.
Claim 79
Dependent Claim
20 words
The system of claim 71 further comprising an optical sensor for sampling the intensity of radiant energy in the cavity.
Claim 80
Dependent Claim
25 words
The system of claim 71, wherein the shield has a thickness selected such that the shield and the substrate heat at substantially the same rate.
Claim 81
Dependent Claim
23 words
The system of claim 71, wherein the shield has a thickness within a factor of three (3) of the thickness of the substrate.
Claim 82
Dependent Claim
17 words
The system of claim 71, wherein the substrate is rotated relative to the supplemental heater during processing.
Claim 83
Dependent Claim
19 words
The system of claim 71, wherein the processing temperature is greater than about six hundred degrees Celsius (600° C.).
Claim 84
Dependent Claim
14 words
The system of claim 71 wherein the supplemental heater comprises silicon carbide coated graphite.
Claim 85
Dependent Claim
11 words
The system of claim 71 wherein the shield comprises silicon carbide.
References Cited (Backward Citations)
US4560286A
Cited
US4350537A
Cited
US4469529A
Cited
US4533820A
Cited
US4493977A
Cited
US4535228A
Cited
US4504730A
Cited
US4535227A
Cited
US4698486A
Cited
US4649261A
Cited
US4750139A
Cited
US4845647A
Cited
US4680451A
Cited
US4755654A
Cited
US5427620A
Cited
US5318634A
Cited
US5117769A
Cited
US4821674A
Cited
US4996942A
Cited
US4993355A
Cited
US5198034A
Cited
US4913929A
Cited
US4975561A
Cited
US4836138A
Cited
US4818327A
Cited
JPS6424726A
Cited
US5034199A
Cited
US4857689A
Cited
US4859079A
Cited
US4956538A
Cited
US4891499A
Cited
US5011794A
Cited
US5156820A
Cited
US5002630A
Cited
US5063031A
Cited
JPH03195928A
Cited
US5317492A
Cited
US5155336A
Cited
US5154512A
Cited
US5310260A
Cited
US5208643A
Cited
US5148714A
Cited
US5165796A
Cited
US5114242A
Cited
US5275976A
Cited
US5293216A
Cited
US5102231A
Cited
US5101764A
Cited
US5166080A
Cited
US5156461A
Cited
US5180226A
Cited
US5296385A
Cited
US5350899A
Cited
US5268989A
Cited
US5367606A
Cited
JPH05335253A
Cited
US5326170A
Cited
US5444217A
Cited
US5683518A
Cited
EP0612862A1
Cited
US5305417A
Cited
US5549756A
Cited
EP0718610A1
Cited
US5660472A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-11-02 | 2002-05-04 | 2002-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-02 | 2006-05-04 | 2006-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-02 | 2010-05-04 | 2010-11-03 | $7700.00 | Window Closed / Lapsed |