Patent US6133550A successfully refreshed from Google Patents.
US6133550A
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US
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Method and apparatus for thermal processing of semiconductor substrates
Assignee: National Technology and Engineering Solutions of Sandia LLC
•
Filing: 1998-08-26
•
Granted: 2000-10-17
•
Expires: 2018-08-26
Abstract
Abstract An improved apparatus and method for thermal processing of semiconductor wafers. The apparatus and method provide the temperature stability and uniformity of a conventional batch furnace as well as the processing speed and reduced time-at-temperature of a lamp-heated rapid thermal processor (RTP). Individual wafers are rapidly inserted into and withdrawn from a furnace cavity held at a nearly constant and isothermal temperature. The speeds of insertion and withdrawal are sufficiently large to limit thermal stresses and thereby reduce or prevent plastic deformation of the wafer as it enters and leaves the furnace. By processing the semiconductor wafer in a substantially isothermal cavity, the wafer temperature and spatial uniformity of the wafer temperature can be ensured by measuring and controlling only temperatures of the cavity walls. Further, peak power requirements are very small compared to lamp-heated RTPs because the cavity temperature is not cycled and the thermal mass of the cavity is relatively large. Increased speeds of insertion and/or removal may also be used with non-isothermal furnaces.
Inventors
- 👤 Stewart K. Griffiths
- 👤 Robert H. Nilson
- 👤 Brad S. Mattson
- 👤 Stephen E. Savas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:23
CPC Classifications
H; H10; H10P; H10P95/00; H10P95/90; H10P72/00; H10P72/06; H10P72/0602; C; C23; C23C; C23C16/00; C23C16/44; C23C16/46; C23C16/54; C30; C30B; C30B25/00; C30B25/02; C30B25/10; C30B31/00; C30B31/06; C30B31/12; H10P72/04; H10P72/0431; H10P72/0434
Claims Analysis
Total Claims: 75
Claim 1
Independent Claim
114 words
An apparatus for rapid thermal processing of semiconductor wafers, comprising: a) a furnace having a base, side walls, and a top, wherein the base, side walls and top of the furnace are provided with heating means and define a cavity maintained at a substantially constant and uniform temperature and adapted to receive a semiconductor wafer, the heating means configured to heat the cavity to a temperature of at least 900° C.; b) means for inserting and withdrawing the wafer into and from the cavity and directly into the ambient; and c) means for controlling the speeds of insertion and withdrawal configured to provide a speed of insertion and withdrawal of at least 0.2 m/sec.
Claim 2
Independent Claim
114 words
An apparatus for rapid thermal processing of semiconductor wafers, comprising: a) a furnace having a base, side walls, and a top, wherein the base, side walls and top of the furnace are provided with heating means and define a cavity maintained at a substantially constant and uniform temperature and adapted to receive a semiconductor wafer, the heating means configured to heat the cavity to a temperature of at least 900° C.; b) means for inserting and withdrawing the wafer into and from the cavity and directly into the ambient; and c) means for controlling the speeds of insertion and withdrawal configured to provide a speed of insertion and withdrawal of at least 0.2 m/sec.
Claim 3
Dependent Claim
22 words
The apparatus of claim 1 further including a plurality of thermocouples attached to the base, side walls and top of said furnace.
Claim 4
Dependent Claim
27 words
The apparatus of claim 1, wherein the base, side walls and top are selected from the group consisting of metals, ceramics, glasses, refractive compounds, and combinations thereof.
Claim 5
Dependent Claim
35 words
The apparatus of claim 1 wherein the means for inserting and withdrawing the wafer is selected from a group consisting of pneumatic drives, ball screw drives, belt-driver rodless actuators and linear servo and stepper motors.
Claim 6
Dependent Claim
12 words
The apparatus of claim 1 wherein the heating means comprise resistance heaters.
Claim 7
Dependent Claim
16 words
The apparatus of claim 5 further including means for controlling power supplied to the resistance heaters.
Claim 8
Dependent Claim
22 words
The apparatus of claim 1 further including means for exposing the semiconductor wafer to reactant gases useful for chemical vapor deposition processing.
Claim 9
Dependent Claim
28 words
The apparatus of claim 1 wherein said means for inserting and withdrawing includes a wafer carrier that provides full support around the wafer perimeter and a radiation shield.
Claim 10
Independent Claim
104 words
A method of rapid thermal processing semiconductor wafers comprising the steps of: a) heating a cavity within a furnace having a base, side walls and top provided with heating means to a substantially constant processing temperature; b) maintaining the heated cavity in a substantially isothermal condition at the processing temperature; c) inserting a semiconductor wafer into the heated isothermal cavity at a speed of at least 0.2 m/s for an isothermal cavity temperature of at least 900° C.; and d) withdrawing the semiconductor wafer from the heated isothermal cavity and directly into the ambient, wherein the speed of withdrawal is at least 0.2 m/sec.
Claim 11
Independent Claim
104 words
A method of rapid thermal processing semiconductor wafers comprising the steps of: a) heating a cavity within a furnace having a base, side walls and top provided with heating means to a substantially constant processing temperature; b) maintaining the heated cavity in a substantially isothermal condition at the processing temperature; c) inserting a semiconductor wafer into the heated isothermal cavity at a speed of at least 0.2 m/s for an isothermal cavity temperature of at least 900° C.; and d) withdrawing the semiconductor wafer from the heated isothermal cavity and directly into the ambient, wherein the speed of withdrawal is at least 0.2 m/sec.
Claim 12
Independent Claim
99 words
An apparatus for thermally processing a semiconductor substrate comprising: a process chamber forming a heated cavity within which the substrate is processed; a heater system for heating the cavity to a processing temperature of at least 800 degrees Celsius; a robot for withdrawing the substrate from the heated cavity after processing into a substantially cooler thermal environment; wherein the temperature of the semiconductor substrate at commencement of withdrawal is at least 700 degrees Celsius hotter than the substantially cooler thermal environment; and the speed at which the semiconductor substrate is withdrawn is greater than about 0.3 meters per second.
Claim 13
Independent Claim
99 words
An apparatus for thermally processing a semiconductor substrate comprising: a process chamber forming a heated cavity within which the substrate is processed; a heater system for heating the cavity to a processing temperature of at least 800 degrees Celsius; a robot for withdrawing the substrate from the heated cavity after processing into a substantially cooler thermal environment; wherein the temperature of the semiconductor substrate at commencement of withdrawal is at least 700 degrees Celsius hotter than the substantially cooler thermal environment; and the speed at which the semiconductor substrate is withdrawn is greater than about 0.3 meters per second.
Claim 14
Dependent Claim
18 words
The apparatus of claim 10 wherein the semiconductor substrate has a diameter of at least about 200 mm.
Claim 15
Dependent Claim
18 words
The apparatus of claim 10 wherein the semiconductor substrate has a diameter of at least about 300 mm.
Claim 16
Dependent Claim
18 words
The apparatus of claim 10 wherein the semiconductor substrate has a diameter of at least about 400 mm.
Claim 17
Dependent Claim
30 words
The apparatus of claim 10 wherein the speed of withdrawal is sufficient to prevent plastic deformation of the semiconductor substrate due to the withdrawal into the substantially cooler thermal environment.
Claim 18
Dependent Claim
52 words
The apparatus of claim 10 wherein the heated cavity is enclosed within heat shielding walls and the heater system includes a heated surface disposed within the heated cavity, further comprising a support for moving the substrate substantially perpendicularly toward the heated surface for processing and away from the heated surface after processing.
Claim 19
Dependent Claim
79 words
The apparatus of claim 14 further comprising a support for the substrate wherein: the robot inserts the substrate into the heated cavity and places the substrate upon the support substantially parallel to the heated surface; the support moves the substrate substantially parallel and closely adjacent to the heated surface for processing and substantially parallel and away from the heated surface after processing; and the robot removes the substrate from the support and withdraws the substrate from the heated cavity.
Claim 20
Dependent Claim
23 words
The apparatus of claim 10 wherein the heater system maintains a substantially isothermal environment in the heated cavity for processing the semiconductor substrate.
Claim 21
Dependent Claim
30 words
The apparatus of claim 16 wherein the speed of withdrawal is sufficient to prevent plastic deformation of the semiconductor substrate due to the withdrawal into the substantially cooler thermal environment.
Claim 22
Dependent Claim
41 words
The apparatus of claim 10 wherein the speed of withdrawal is sufficient to substantially reduce plastic deformation of the substrate relative to the level of plastic deformation that would result at a speed of withdrawal of about 0.2 meters per second.
Claim 23
Dependent Claim
18 words
The apparatus of claim 10 wherein the speed of withdrawal is greater than about 0.5 meters per second.
Claim 24
Dependent Claim
18 words
The apparatus of claim 10 wherein the speed of withdrawal is greater than about 0.75 meters per second.
Claim 25
Dependent Claim
18 words
The apparatus of claim 10 wherein the speed of withdrawal is greater than about 1 meter per second.
Claim 26
Dependent Claim
18 words
The apparatus of claim 10 wherein the speed of withdrawal is greater than about 1.5 meters per second.
Claim 27
Dependent Claim
30 words
The apparatus of claim 10 wherein the speed of withdrawal is greater than about 2 meters per second and the substrate has a diameter of at least about 300 mm.
Claim 28
Dependent Claim
19 words
The apparatus of claim 10 wherein the speed of withdrawal is between about 0.4 to 1.2 meters per second.
Claim 29
Dependent Claim
42 words
The apparatus of claim 10 wherein the speed of withdrawal is between about 0.3 to 1.2 meters per second and is selected such that plastic deformation defects are formed which are limited to point-like defects with lengths less than about 100 microns.
Claim 30
Dependent Claim
16 words
The apparatus of claim 23 wherein the substrate has a diameter of at least 300 mm.
Claim 31
Dependent Claim
21 words
The apparatus of claim 10 wherein the substantially cooler thermal environment has a temperature of less than about 200 degrees Celsius.
Claim 32
Dependent Claim
28 words
The apparatus of claim 10 wherein the processing temperature is greater than about 1000 degrees Celsius and the semiconductor substrate has a diameter of at least 150 mm.
Claim 33
Dependent Claim
28 words
The apparatus of claim 10 wherein the processing temperature is greater than about 1100 degrees Celsius and the semiconductor substrate has a diameter of at least 150 mm.
Claim 34
Dependent Claim
31 words
The apparatus of claim 10 further comprising a heat shield for the edge of the semiconductor substrate which decreases the rate of cooling at the edge of the substrate after withdrawal.
Claim 35
Dependent Claim
60 words
The apparatus of claim 10 further comprising a substrate carrier having an areal thermal mass substantially equal to the substrate and having a thickness within a factor of four of the substrate thickness, wherein the substrate carrier extends beyond the edge of the substrate by a distance equal to at least one half of the height of the heated cavity.
Claim 36
Dependent Claim
54 words
The apparatus of claim 10 further comprising a substrate carrier supporting the substrate around the periphery of the substrate, wherein the substrate carrier is moved substantially along the plane of the substrate to accelerate the substrate for insertion and withdrawal by applying a force to the edge of the substrate through the substrate carrier.
Claim 37
Dependent Claim
29 words
The apparatus of claim 10 further comprising a robot for inserting the substrate into the heated cavity for processing at a speed of insertion of at least 0.3 m/sec.
Claim 38
Dependent Claim
17 words
The apparatus of claim 34, wherein the speed of withdrawal is greater than the speed of insertion.
Claim 39
Independent Claim
86 words
A method for thermally processing a semiconductor substrate comprising: heating the semiconductor substrate in a heated cavity to a processing temperature of at least 800 degrees Celsius; and withdrawing the semiconductor substrate from the heated cavity after processing into a substantially cooler thermal environment wherein: the temperature of the semiconductor substrate at commencement of withdrawal is at least 700 degrees Celsius hotter than the substantially cooler thermal environment; and the speed at which the semiconductor substrate is withdrawn is greater than about 0.3 meters per second.
Claim 40
Independent Claim
86 words
A method for thermally processing a semiconductor substrate comprising: heating the semiconductor substrate in a heated cavity to a processing temperature of at least 800 degrees Celsius; and withdrawing the semiconductor substrate from the heated cavity after processing into a substantially cooler thermal environment wherein: the temperature of the semiconductor substrate at commencement of withdrawal is at least 700 degrees Celsius hotter than the substantially cooler thermal environment; and the speed at which the semiconductor substrate is withdrawn is greater than about 0.3 meters per second.
Claim 41
Dependent Claim
17 words
The method of claim 36 wherein the semiconductor substrate has a diameter of at least 300 mm.
Claim 42
Dependent Claim
30 words
The method of claim 36 wherein the speed of withdrawal is sufficient to prevent plastic deformation of the semiconductor substrate due to the withdrawal into the substantially cooler thermal environment.
Claim 43
Dependent Claim
18 words
The method of claim 36 wherein the substrate is inserted into and removed from the heated cavity laterally.
Claim 44
Dependent Claim
26 words
The method of claim 36 further comprising the step of maintaining the heated cavity at a substantially uniform and constant temperature for processing the semiconductor substrate.
Claim 45
Dependent Claim
30 words
The method of claim 40 wherein the speed of withdrawal is sufficient to prevent plastic deformation of the semiconductor substrate due to the withdrawal into the substantially cooler thermal environment.
Claim 46
Dependent Claim
41 words
The method of claim 36 wherein the speed of withdrawal is sufficient to substantially reduce plastic deformation of the substrate relative to the level of plastic deformation that would result at a speed of withdrawal of about 0.2 meters per second.
Claim 47
Dependent Claim
18 words
The method of claim 36 wherein the speed of withdrawal is greater than about 0.5 meters per second.
Claim 48
Dependent Claim
18 words
The method of claim 36 wherein the speed of withdrawal is greater than about 0.75 meters per second.
Claim 49
Dependent Claim
18 words
The method of claim 36 wherein the speed of withdrawal is greater than about 1 meter per second.
Claim 50
Dependent Claim
18 words
The method of claim 36 wherein the speed of withdrawal is greater than about 1.5 meters per second.
Claim 51
Dependent Claim
30 words
The method of claim 36 wherein the speed of withdrawal is greater than about 2 meters per second and the substrate has a diameter of at least about 300 mm.
Claim 52
Dependent Claim
42 words
The method of claim 36 wherein the speed of withdrawal is between about 0.3 to 1.2 meters per second and is selected such that plastic deformation defects are formed which are limited to point-like defects with lengths less than about 100 microns.
Claim 53
Dependent Claim
16 words
The method of claim 36 wherein the processing temperature is greater than about 1000 degrees Celsius.
Claim 54
Dependent Claim
28 words
The method of claim 36 wherein the processing temperature is greater than about 1100 degrees Celsius and the substrate has a diameter of at least about 150 mm.
Claim 55
Independent Claim
119 words
A method for thermally processing a semiconductor substrate comprising: heating the semiconductor substrate in a first thermal environment to a processing temperature of at least 900 degrees Celsius; providing a second thermal environment to which the substrate is withdrawn after processing, wherein a temperature differential exists between the first thermal environment and the second thermal environment of at least 500 degrees Celsius; moving the substrate from the first thermal environment to the second thermal environment such that first and second portions of the substrate are exposed to the first and second thermal environments, respectively, for a period of time, wherein the substrate is moved at sufficient speed such that the period of time is less than about 0.75 seconds.
Claim 56
Independent Claim
119 words
A method for thermally processing a semiconductor substrate comprising: heating the semiconductor substrate in a first thermal environment to a processing temperature of at least 900 degrees Celsius; providing a second thermal environment to which the substrate is withdrawn after processing, wherein a temperature differential exists between the first thermal environment and the second thermal environment of at least 500 degrees Celsius; moving the substrate from the first thermal environment to the second thermal environment such that first and second portions of the substrate are exposed to the first and second thermal environments, respectively, for a period of time, wherein the substrate is moved at sufficient speed such that the period of time is less than about 0.75 seconds.
Claim 57
Dependent Claim
14 words
The method of claim 51 wherein the differential is at least 900 degrees Celsius.
Claim 58
Dependent Claim
16 words
The method of claim 51 wherein the substrate has a diameter of at least 300 mm.
Claim 59
Dependent Claim
16 words
The method of claim 52 wherein the period of time is less than about 0.5 seconds.
Claim 60
Dependent Claim
34 words
The method of claim 51 wherein the processing temperature is at least 1100 degrees Celsius, the differential is at least 1000 degrees Celsius, and the period of time is less than about 0.4 seconds.
Claim 61
Dependent Claim
13 words
The method of claim 51 wherein the first thermal environment is substantially isothermal.
Claim 62
Dependent Claim
13 words
The method of claim 55 wherein the first thermal environment is substantially isothermal.
Claim 63
Dependent Claim
38 words
The method of claim 51 wherein the speed of withdrawal is sufficient to substantially reduce plastic deformation relative to that which would result if the substrate were exposed to the differential for between about 1 to 2 seconds.
Claim 64
Dependent Claim
21 words
The method of claim 51 wherein the speed of withdrawal is sufficient to substantially prevent plastic deformation of the semiconductor substrate.
Claim 65
Independent Claim
117 words
A method for thermally processing a semiconductor substrate in a heated cavity, wherein removal of the substrate from the heated cavity during multiple cycles at speeds of about 0.2 meters per second would result in significant plastic deformation for a desired processing temperature, the method comprising: heating the semiconductor substrate to the desired processing temperature in the heated cavity; and removing the substrate from the heated cavity after processing at a speed greater than about 0.3 meters per second wherein the speed is sufficient to substantially reduce the level of plastic deformation after multiple cycles relative to the level of plastic deformation that would occur if removal speeds of about 0.2 meters per second had been used.
Claim 66
Independent Claim
117 words
A method for thermally processing a semiconductor substrate in a heated cavity, wherein removal of the substrate from the heated cavity during multiple cycles at speeds of about 0.2 meters per second would result in significant plastic deformation for a desired processing temperature, the method comprising: heating the semiconductor substrate to the desired processing temperature in the heated cavity; and removing the substrate from the heated cavity after processing at a speed greater than about 0.3 meters per second wherein the speed is sufficient to substantially reduce the level of plastic deformation after multiple cycles relative to the level of plastic deformation that would occur if removal speeds of about 0.2 meters per second had been used.
Claim 67
Dependent Claim
21 words
The method of claim 60 further comprising the step of maintaining the heated cavity at a substantially constant and uniform temperature.
Claim 68
Dependent Claim
17 words
The method of claim 60 wherein the speed of removal is sufficient to substantially prevent plastic deformation.
Claim 69
Dependent Claim
29 words
The method of claim 60 wherein the processing temperature is greater than about 1000 degrees Celsius and the speed of removal is greater than about 0.5 meters per second.
Claim 70
Dependent Claim
29 words
The method of claim 60 wherein the processing temperature is greater than about 1000 degrees Celsius and the speed of removal is greater than about 0.75 meters per second.
Claim 71
Dependent Claim
39 words
The method of claim 60 wherein the processing temperature is greater than about 1100 degrees Celsius and the speed of removal is greater than about 1 meter per second and the substrate has a diameter of about 300 mm.
Claim 72
Dependent Claim
16 words
The method of claim 64 wherein the substrate has a diameter of at least 300 mm.
Claim 73
Dependent Claim
32 words
The method of claim 60 wherein the speed of removal is selected such that plastic deformation defects are formed which are limited to point-like defects with lengths less than about 100 microns.
Claim 74
Dependent Claim
19 words
The method of claim 67 wherein the speed of removal is between about 0.3 and 1 meters per second.
Claim 75
Dependent Claim
50 words
The method of claim 60 wherein defects of greater than 1 mm in length would be formed after multiple cycles at a removal speed of 0.2 meters per second and wherein the speed of removal is selected such that defects of greater than 1 mm in length are substantially avoided.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2003-10-17 | 2004-04-17 | 2004-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-10-17 | 2008-04-17 | 2008-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-10-17 | 2012-04-17 | 2012-10-17 | $7700.00 | Window Closed / Lapsed |