Patent US6090718A successfully refreshed from Google Patents.
US6090718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dry etching method for semiconductor substrate
Assignee: Denso Corp
•
Filing: 1997-12-17
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Granted: 2000-07-18
•
Expires: 2017-12-17
Abstract
Abstract After performing an etching process with respect to one substrate, the substrate is taken out from an etching chamber. Then, a dummy substrate is disposed in the etching chamber and a cleaning process is performed. The cleaning process includes a cleaning step for etching reaction products produced during the etching process to be removed, a seasoning step for adjusting the atmosphere within the etching chamber and the temperature of the substrate, and a purge step for removing suspended foreign materials without generating plasma. By performing the cleaning process, the successive etching process can be performed without generating any black silicon on the substrate, thereby attaining a high production yield.
Inventors
- 👤 Hajime Soga
- 👤 Kenji Kondo
- 👤 Eiji Ishikawa
- 👤 Yoshikazu Sakano
- 👤 Yuji Ichikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:59
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/04; H10P72/0402; H10P72/0418; H10P72/0421; Y; Y10; Y10S; Y10S438/00; Y10S438/905; Y10S438/906
Claims Analysis
Total Claims: 53
Claim 1
Independent Claim
192 words
A method for respectively dry-etching first and second substrates made of silicon, comprising: etching the first substrate within an etching chamber; taking the first substrate out of the etching chamber; disposing a dummy substrate having a surface portion within the etching chamber, the surface portion being made of a material different than silicon; etching a reaction product produced in the step of etching the first substrate; taking the dummy substrate out of the etching chamber; disposing the second substrate within the etching chamber; and etching the second substrate, wherein said etching of the reaction product includes a cleaning step of etching the reaction product, and a seasoning step of removing the reaction product from the etching chamber and adjusting an atmosphere within the etching chamber and a temperature of the dummy substrate, wherein HBr, SiF 4 , and O 2 gases are used in the steps of etching the first and second substrates and in the seasoning step, and wherein a total flow rate of the HBr, SiF 4 , and O 2 which is introduced into the etching chamber in the seasoning step is smaller than that in the etching steps.
Claim 2
Independent Claim
192 words
A method for respectively dry-etching first and second substrates made of silicon, comprising: etching the first substrate within an etching chamber; taking the first substrate out of the etching chamber; disposing a dummy substrate having a surface portion within the etching chamber, the surface portion being made of a material different than silicon; etching a reaction product produced in the step of etching the first substrate; taking the dummy substrate out of the etching chamber; disposing the second substrate within the etching chamber; and etching the second substrate, wherein said etching of the reaction product includes a cleaning step of etching the reaction product, and a seasoning step of removing the reaction product from the etching chamber and adjusting an atmosphere within the etching chamber and a temperature of the dummy substrate, wherein HBr, SiF 4 , and O 2 gases are used in the steps of etching the first and second substrates and in the seasoning step, and wherein a total flow rate of the HBr, SiF 4 , and O 2 which is introduced into the etching chamber in the seasoning step is smaller than that in the etching steps.
Claim 3
Dependent Claim
21 words
The method of claim 1, wherein a flow rate of the SiF 4 gas in the seasoning step is substantially zero.
Claim 4
Independent Claim
249 words
A method for respectively dry-etching first and second substrates made of silicon, comprising: etching the first substrate within an etching chamber; taking the first substrate out of the etching chamber; disposing a dummy substrate having a surface portion within the etching chamber, the surface portion being made of a material different than silicon; etching a reaction product produced in the step of etching the first substrate; taking the dummy substrate out of the etching chamber; disposing the second substrate within the etching chamber; and etching the second substrate, wherein said etching of the reaction product includes a cleaning step of etching the reaction product, and a seasoning step of removing the reaction product from the etching chamber and adjusting an atmosphere within the etching chamber and a temperature of the dummy substrate, wherein in said etching of the first substrate, the first substrate is fixed to an electrode by a clamp within the etching chamber, wherein said method further includes a purge step of removing foreign materials from the etching chamber in which a portion of the foreign materials is suspended within the etching chamber and another portion of the foreign materials is attached to the electrode, a wall of the etching chamber, and the clamp, the purge step being performed without generating plasma after performing the cleaning and seasoning steps, and wherein a gas used in the purge step has a composition substantially the same as that used in the steps of etching the first and second substrates.
Claim 5
Independent Claim
249 words
A method for respectively dry-etching first and second substrates made of silicon, comprising: etching the first substrate within an etching chamber; taking the first substrate out of the etching chamber; disposing a dummy substrate having a surface portion within the etching chamber, the surface portion being made of a material different than silicon; etching a reaction product produced in the step of etching the first substrate; taking the dummy substrate out of the etching chamber; disposing the second substrate within the etching chamber; and etching the second substrate, wherein said etching of the reaction product includes a cleaning step of etching the reaction product, and a seasoning step of removing the reaction product from the etching chamber and adjusting an atmosphere within the etching chamber and a temperature of the dummy substrate, wherein in said etching of the first substrate, the first substrate is fixed to an electrode by a clamp within the etching chamber, wherein said method further includes a purge step of removing foreign materials from the etching chamber in which a portion of the foreign materials is suspended within the etching chamber and another portion of the foreign materials is attached to the electrode, a wall of the etching chamber, and the clamp, the purge step being performed without generating plasma after performing the cleaning and seasoning steps, and wherein a gas used in the purge step has a composition substantially the same as that used in the steps of etching the first and second substrates.
Claim 6
Dependent Claim
56 words
The method of claim 3, wherein: gas conditions in the purge step are substantially the same as those in the steps of etching the first and second substrates; and the purge step is performed without generating plasma, while the steps of etching the first and second substrates are performed to generate plasma within the etching chamber.
Claim 7
Independent Claim
311 words
A method for respectively dry-etching first and second substrates made of silicon, comprising: etching the first substrate within an etching chamber; taking the first substrate out of the etching chamber; disposing a dummy substrate having a surface portion within the etching chamber, the surface portion being made of a material different than silicon; etching a reaction product produced while etching the first substrate; taking the dummy substrate out of the etching chamber; disposing the second substrate within the etching chamber; and etching the second substrate, wherein said etching of the reaction product includes a cleaning step of etching the reaction product, and a seasoning step of removing the reaction product from the etching chamber and adjusting an atmosphere within the etching chamber and a temperature of the dummy substrate, wherein in the step of etching the first substrate, the first substrate is fixed to an electrode by a clamp within the etching chamber, wherein said method further includes a purge step of removing foreign materials from the etching chamber in which a portion of the foreign materials is suspended within the etching chamber and another portion of the foreign materials is attached to the electrode, a wall of the etching chamber, and the clamp, the purge step being performed without generating plasma after performing the cleaning and seasoning steps, wherein the dummy substrate has an SiO 2 layer on a surface thereof, and wherein the purge step is performed under conditions such that an etching speed ratio of the first and second substrates with respect to the SiO 2 layer is small compared to that in the steps of etching the first and second substrates if plasma is generated in the purge step, and such that a flow rate of a gas used in the purge step is larger than that in the steps of etching the first and second substrates.
Claim 8
Independent Claim
311 words
A method for respectively dry-etching first and second substrates made of silicon, comprising: etching the first substrate within an etching chamber; taking the first substrate out of the etching chamber; disposing a dummy substrate having a surface portion within the etching chamber, the surface portion being made of a material different than silicon; etching a reaction product produced while etching the first substrate; taking the dummy substrate out of the etching chamber; disposing the second substrate within the etching chamber; and etching the second substrate, wherein said etching of the reaction product includes a cleaning step of etching the reaction product, and a seasoning step of removing the reaction product from the etching chamber and adjusting an atmosphere within the etching chamber and a temperature of the dummy substrate, wherein in the step of etching the first substrate, the first substrate is fixed to an electrode by a clamp within the etching chamber, wherein said method further includes a purge step of removing foreign materials from the etching chamber in which a portion of the foreign materials is suspended within the etching chamber and another portion of the foreign materials is attached to the electrode, a wall of the etching chamber, and the clamp, the purge step being performed without generating plasma after performing the cleaning and seasoning steps, wherein the dummy substrate has an SiO 2 layer on a surface thereof, and wherein the purge step is performed under conditions such that an etching speed ratio of the first and second substrates with respect to the SiO 2 layer is small compared to that in the steps of etching the first and second substrates if plasma is generated in the purge step, and such that a flow rate of a gas used in the purge step is larger than that in the steps of etching the first and second substrates.
Claim 9
Independent Claim
158 words
A method for respectively dry-etching first and second substrates made of silicon, comprising: etching the first substrate within an etching chamber; taking the first substrate out of the etching chamber; disposing a dummy substrate having a surface portion within the etching chamber, the surface portion being made of a material different than silicon; etching a reaction product produced while etching the first substrate; taking the dummy substrate out of the etching chamber; disposing the second substrate within the etching chamber; and etching the second substrate, wherein said etching of the reaction product includes a cleaning step of etching the reaction product, and a seasoning step of removing the reaction product from the etching chamber and adjusting an atmosphere within the etching chamber and a temperature of the dummy substrate, and wherein the cleaning step uses a gas having an etching speed with respect to the dummy substrate smaller than that with respect to the first and second substrates.
Claim 10
Independent Claim
158 words
A method for respectively dry-etching first and second substrates made of silicon, comprising: etching the first substrate within an etching chamber; taking the first substrate out of the etching chamber; disposing a dummy substrate having a surface portion within the etching chamber, the surface portion being made of a material different than silicon; etching a reaction product produced while etching the first substrate; taking the dummy substrate out of the etching chamber; disposing the second substrate within the etching chamber; and etching the second substrate, wherein said etching of the reaction product includes a cleaning step of etching the reaction product, and a seasoning step of removing the reaction product from the etching chamber and adjusting an atmosphere within the etching chamber and a temperature of the dummy substrate, and wherein the cleaning step uses a gas having an etching speed with respect to the dummy substrate smaller than that with respect to the first and second substrates.
Claim 11
Independent Claim
158 words
A method for respectively dry-etching first and second substrates made of silicon, comprising: etching the first substrate within an etching chamber; taking the first substrate out of the etching chamber; disposing a dummy substrate having a surface portion within the etching chamber, the surface portion being made of a material different than silicon; etching a reaction product while etching the first substrate; taking the dummy substrate out of the etching chamber; disposing the second substrate within the etching chamber; and etching the second substrate, wherein said etching of the reaction product includes a cleaning step of etching the reaction product, and a seasoning step of removing the reaction product from the etching chamber and adjusting an atmosphere within the etching chamber and a temperature of the dummy substrate, and wherein the cleaning step includes a first cleaning step performed at a first pressure and a second cleaning step performed at a second pressure different from the first pressure.
Claim 12
Independent Claim
158 words
A method for respectively dry-etching first and second substrates made of silicon, comprising: etching the first substrate within an etching chamber; taking the first substrate out of the etching chamber; disposing a dummy substrate having a surface portion within the etching chamber, the surface portion being made of a material different than silicon; etching a reaction product while etching the first substrate; taking the dummy substrate out of the etching chamber; disposing the second substrate within the etching chamber; and etching the second substrate, wherein said etching of the reaction product includes a cleaning step of etching the reaction product, and a seasoning step of removing the reaction product from the etching chamber and adjusting an atmosphere within the etching chamber and a temperature of the dummy substrate, and wherein the cleaning step includes a first cleaning step performed at a first pressure and a second cleaning step performed at a second pressure different from the first pressure.
Claim 13
Independent Claim
98 words
A method for etching a silicon substrate, comprising: etching the substrate with an etching gas within an etching chamber, the substrate being fixed to an electrode by a clamp; a purge step of removing foreign materials that are suspended within the etching chamber and attached to the substrate, the electrode, a wall of the etching chamber, and the clamp, the purge step being performed while flowing a purge gas in a non-plasma state; and further etching the substrate with the etching gas, wherein the purge gas has a composition substantially the same as that of the etching gas.
Claim 14
Independent Claim
98 words
A method for etching a silicon substrate, comprising: etching the substrate with an etching gas within an etching chamber, the substrate being fixed to an electrode by a clamp; a purge step of removing foreign materials that are suspended within the etching chamber and attached to the substrate, the electrode, a wall of the etching chamber, and the clamp, the purge step being performed while flowing a purge gas in a non-plasma state; and further etching the substrate with the etching gas, wherein the purge gas has a composition substantially the same as that of the etching gas.
Claim 15
Dependent Claim
48 words
The method of claim 8, wherein: a flow rate of purge gas is substantially the same as that of the etching gas, and the purge step is performed in the non-plasma state, while said etching and said further etching are performed to generate plasma within the etching chamber.
Claim 16
Independent Claim
179 words
A method for etching a silicon substrate, comprising: etching the substrate with an etching gas within an etching chamber, the substrate being fixed to an electrode by a clamp; a purge step of removing foreign materials that are suspended within the etching chamber and attached to the substrate, the electrode, a wall of the etching chamber, and the clamp, the purge step being performed while flowing a purge gas in a non-plasma state; and further etching the substrate with the etching gas, wherein the substrate has an etching mask formed on a surface thereof, the etching mask being made of SiO 2 and having an opening at a specific portion, and wherein the purge step is performed under conditions such that an etching speed ratio of the substrate with respect to the etching mask is small compared to that in the first and second etching steps if plasma is generated in the purge step, and such that a flow rate of the purge gas is larger than that of the etching gas in the first and second etching steps.
Claim 17
Independent Claim
179 words
A method for etching a silicon substrate, comprising: etching the substrate with an etching gas within an etching chamber, the substrate being fixed to an electrode by a clamp; a purge step of removing foreign materials that are suspended within the etching chamber and attached to the substrate, the electrode, a wall of the etching chamber, and the clamp, the purge step being performed while flowing a purge gas in a non-plasma state; and further etching the substrate with the etching gas, wherein the substrate has an etching mask formed on a surface thereof, the etching mask being made of SiO 2 and having an opening at a specific portion, and wherein the purge step is performed under conditions such that an etching speed ratio of the substrate with respect to the etching mask is small compared to that in the first and second etching steps if plasma is generated in the purge step, and such that a flow rate of the purge gas is larger than that of the etching gas in the first and second etching steps.
Claim 18
Independent Claim
122 words
A method of dry-etching first and second substrates made of silicon, comprising: etching the first substrate within an etching chamber; removing the first substrate from the etching chamber; disposing a dummy substrate within the etching chamber; performing a cleaning step for etching a reaction product to thereby produce foreign materials, the reaction product being produced when the first substrate is etched; performing a purge step for removing the foreign materials from the etching chamber without generating plasma, the purge step being performed with a gas having a composition that is substantially the same as that used for etching the first substrate; removing the dummy substrate from the etching chamber; disposing the second substrate within the etching chamber; and etching the second substrate.
Claim 19
Independent Claim
122 words
A method of dry-etching first and second substrates made of silicon, comprising: etching the first substrate within an etching chamber; removing the first substrate from the etching chamber; disposing a dummy substrate within the etching chamber; performing a cleaning step for etching a reaction product to thereby produce foreign materials, the reaction product being produced when the first substrate is etched; performing a purge step for removing the foreign materials from the etching chamber without generating plasma, the purge step being performed with a gas having a composition that is substantially the same as that used for etching the first substrate; removing the dummy substrate from the etching chamber; disposing the second substrate within the etching chamber; and etching the second substrate.
Claim 20
Dependent Claim
44 words
The method of claim 11, further comprising performing a seasoning step for removing the reaction product from the etching chamber and adjusting an atmosphere within the etching chamber and a temperature of the dummy substrate, said seasoning step being performed before the purge step.
Claim 21
Dependent Claim
32 words
The method of claim 12, wherein the seasoning step is performed with a gas mixture that minimizes formation of a reaction product containing silicon and oxygen on the first and second substrates.
Claim 22
Dependent Claim
26 words
The method of claim 12, wherein the seasoning step is performed with a gas mixture not containing both of SiF 4 and O 2 gases together.
Claim 23
Dependent Claim
64 words
The method of claim 12, wherein: HBr, SiF 4 , and O 2 gases are used in the steps of etching the first and second substrates and in the seasoning step; and a total flow rate of the HBr, SiF 4 , and O 2 which is introduced into the etching chamber in the seasoning step is smaller than that in the etching steps.
Claim 24
Dependent Claim
21 words
The method of claim 15, wherein a flow rate of the SiF 4 gas in the seasoning step is substantially zero.
Claim 25
Dependent Claim
29 words
The method of claim 11, wherein in the step of etching the first substrate, the first substrate is fixed to an electrode by a clamp within the etching chamber.
Claim 26
Dependent Claim
56 words
The method of claim 11, wherein: gas conditions in the purge step are substantially the same as those in the steps of etching the first and second substrates, and the purge step is performed without generating plasma, while the steps of etching the first and second substrates are performed to generate plasma within the etching chamber.
Claim 27
Dependent Claim
96 words
The method of claim 11, wherein: the dummy substrate has an SiO 2 layer on a surface thereof; and the purge step is performed under conditions such that an etching speed ratio of the first and second substrates with respect to the SiO 2 layer is small compared to that in the steps of etching the first and second substrates if plasma is generated in the purge step, and such that a flow rate of a gas used in the purge step is larger than that in the steps of etching the first and second substrates.
Claim 28
Dependent Claim
26 words
The method of claim 11, further including a step of stabilizing a pressure within the etching chamber before performing the step of etching the second substrate.
Claim 29
Dependent Claim
33 words
The method of claim 20, further including a step of stabilizing a flow rate of a gas that is introduced into the etching chamber before performing the step of etching the second substrate.
Claim 30
Dependent Claim
35 words
The method of claim 11, wherein the cleaning step is performed with a gas having an etching speed with respect to the dummy substrate smaller than that with respect to the first and second substrates.
Claim 31
Dependent Claim
34 words
The method of claim 11, wherein the cleaning step includes a first cleaning step performed at a first pressure and a second cleaning step performed at a second pressure different from the first pressure.
Claim 32
Dependent Claim
21 words
The method of claim 11, wherein the cleaning step uses a gas containing one of SF 6 and NF 3 gases.
Claim 33
Dependent Claim
13 words
The method of claim 11, wherein the reaction product contains silicon and oxygen.
Claim 34
Dependent Claim
18 words
The method of claim 11, wherein the dummy substrate has an SiO 2 layer on a surface thereof.
Claim 35
Dependent Claim
29 words
The method of claim 11, wherein the first substrate is the same as the second substrate, and is etched before and after the step of etching the reaction product.
Claim 36
Independent Claim
116 words
A method of dry-etching first and second substrates made of silicon, said method comprising: etching the first substrate within an etching chamber with an etching gas; removing the first substrate from the etching chamber; disposing a dummy substrate within the etching chamber; performing a cleaning step for etching a reaction product with a cleaning gas, the reaction product being produced when the first substrate is etched; removing the dummy substrate from the etching chamber; disposing the second substrate within the etching chamber; and etching the second substrate, wherein the etching gas has a composition capable of producing silicon dioxide as the reaction product in an amount which is larger than that produced by the cleaning gas.
Claim 37
Independent Claim
116 words
A method of dry-etching first and second substrates made of silicon, said method comprising: etching the first substrate within an etching chamber with an etching gas; removing the first substrate from the etching chamber; disposing a dummy substrate within the etching chamber; performing a cleaning step for etching a reaction product with a cleaning gas, the reaction product being produced when the first substrate is etched; removing the dummy substrate from the etching chamber; disposing the second substrate within the etching chamber; and etching the second substrate, wherein the etching gas has a composition capable of producing silicon dioxide as the reaction product in an amount which is larger than that produced by the cleaning gas.
Claim 38
Dependent Claim
34 words
The method of claim 28, further comprising a seasoning step for removing the reaction product from the etching chamber and adjusting an atmosphere within the etching chamber and a temperature of the dummy substrate.
Claim 39
Dependent Claim
32 words
The method of claim 29, wherein the seasoning step is performed with a gas mixture that minimizes formation of a reaction product containing silicon and oxygen on the first and second substrates.
Claim 40
Dependent Claim
26 words
The method of claim 29, wherein the seasoning step is performed with a mixture gas not containing both of SiF 4 and O 2 gases together.
Claim 41
Dependent Claim
64 words
The method of claim 29, wherein: HBr, SiF 4 , and O 2 gases are used in the steps of etching the first and second substrates and in the seasoning step; and a total flow rate of the HBr, SiF 4 , and O 2 which is introduced into the etching chamber in the seasoning step is smaller than that in the etching steps.
Claim 42
Dependent Claim
21 words
The method of claim 32, wherein a flow rate of the SiF 4 gas in the seasoning step is substantially zero.
Claim 43
Dependent Claim
18 words
The method of claim 29, wherein the seasoning step is performed while generating plasma within the etching chamber.
Claim 44
Dependent Claim
31 words
The method of claim 29, further comprising a purge step for removing foreign materials remaining within the etching chamber after the seasoning step, the purge step being performed without generating plasma.
Claim 45
Dependent Claim
55 words
The method of claim 35, gas conditions in the purge step are substantially the same as those in the steps of etching the first and second substrates, and the purge step is performed without generating plasma, while the steps of etching the first and second substrates are performed to generate plasma within the etching chamber.
Claim 46
Dependent Claim
96 words
The method of claim 35, wherein: the dummy substrate has an SiO 2 layer on a surface thereof; and the purge step is performed under conditions such that an etching speed ratio of the first and second substrates with respect to the SiO 2 layer is small compared to that in the steps of etching the first and second substrates if plasma is generated in the purge step, and such that a flow rate of a gas used in the purge step is larger than that in the steps of etching the first and second substrates.
Claim 47
Dependent Claim
26 words
The method of claim 28, further including a step of stabilizing a pressure within the etching chamber before performing the step of etching the second substrate.
Claim 48
Dependent Claim
33 words
The method of claim 38, further including a step of stabilizing a flow rate of a gas that is introduced into the etching chamber before performing the step of etching the second substrate.
Claim 49
Dependent Claim
35 words
The method of claim 28, wherein the cleaning step is performed with a gas having an etching speed with respect to the dummy substrate smaller than that with respect to the first and second substrates.
Claim 50
Dependent Claim
34 words
The method of claim 28, wherein the cleaning step includes a first cleaning step performed at a first pressure and a second cleaning step performed at a second pressure different from the first pressure.
Claim 51
Dependent Claim
21 words
The method of claim 28, wherein the cleaning step uses a gas containing one of SF 6 and NF 3 gases.
Claim 52
Dependent Claim
18 words
The method of claim 28, wherein the dummy substrate has an SiO 2 layer on a surface thereof.
Claim 53
Dependent Claim
29 words
The method of claim 28, wherein the first substrate is the same as the second substrate, and is etched before and after the step of etching the reaction product.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-07-18 | 2004-01-17 | 2004-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-07-18 | 2008-01-17 | 2008-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-07-18 | 2012-01-17 | 2012-07-18 | $7700.00 | Window Closed / Lapsed |