US5824604A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrocarbon-enhanced dry stripping of photoresist
Assignee: Mattson Technology Inc
•
Filing: 1996-01-23
•
Granted: 1998-10-20
•
Expires: 2016-01-23
Abstract
Abstract Means for increasing the selectivity of photoresist stripping to oxide etching are disclosed. A plasma of an oxidizing gas, a fluoride-containing compound, and a hydrocarbon contains reactive species that preferentially strip photoresist from a substrate with little etching of oxide on the substrate's surface when the reactive species contact the substrate. The reactor, compositions, and methods disclosed are particularly useful in processes for etching silicon wafers to form semiconductor or microelectromechanical devices.
Inventors
- 👤 Ronny Bar-Gadda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:09
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/286; H10P50/287; G; G03; G03F; G03F7/00; G03F7/26; G03F7/42; G03F7/427
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
141 words
A process for removing hardened or implanted photoresist from a silicon wafer comprising a. placing the silicon wafer having hardened or implanted photoresist and oxide thereon into the wafer processing chamber of a plasma-generating reactor; b. forming reactive species by generating a plasma of a gas comprising oxygen, a halogen-containing compound, and a hydrocarbon under conditions capable of causing undesired etching of the oxide in the absence of the hydrocarbon, wherein the reactive species include ions formed from the hydrocarbon; c. exposing the surface of the silicon wafer to reactive species from the plasma, including at least some of the ions formed from the hydrocarbon: and d. maintaining the flow of the hydrocarbon such that the selectivity of etching of the photoresist relative to the oxide is substantially increased over the selectivity that would exist in the absence of the hydrocarbon.
Claim 2
Dependent Claim
141 words
A process for removing hardened or implanted photoresist from a silicon wafer comprising a. placing the silicon wafer having hardened or implanted photoresist and oxide thereon into the wafer processing chamber of a plasma-generating reactor; b. forming reactive species by generating a plasma of a gas comprising oxygen, a halogen-containing compound, and a hydrocarbon under conditions capable of causing undesired etching of the oxide in the absence of the hydrocarbon, wherein the reactive species include ions formed from the hydrocarbon; c. exposing the surface of the silicon wafer to reactive species from the plasma, including at least some of the ions formed from the hydrocarbon: and d. maintaining the flow of the hydrocarbon such that the selectivity of etching of the photoresist relative to the oxide is substantially increased over the selectivity that would exist in the absence of the hydrocarbon.
Claim 3
Dependent Claim
57 words
The process of claim 1 wherein the fluorine-containing compound and hydrocarbon are present in the plasma in amounts sufficient that gases formed below the surface of the photoresist during stripping diffuse out of the photoresist at a rate which provides a gas pressure within the photoresist that is less than the gas pressure which causes photoresist popping.
Claim 4
Dependent Claim
68 words
The process of claim 1 wherein the energy of the plasma and the oxygen, fluorine-containing compound, and hydrocarbon are selected to produce an amount and type of reactive species sufficient that gases formed below the surface of the photoresist during stripping diffuse out of the photoresist at a rate which provides a gas pressure within the photoresist that is less than the gas pressure which causes photoresist popping.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein the halogen-containing compound comprises SF 6 .
Claim 6
Dependent Claim
12 words
The process of claim 1 wherein the hydrocarbon is an aliphatic hydrocarbon.
Claim 7
Dependent Claim
10 words
The process of claim 1 wherein the hydrocarbon is substituted.
Claim 8
Dependent Claim
11 words
The process of claim 1 wherein the hydrocarbon comprises an alkane.
Claim 9
Dependent Claim
10 words
The process of claim 1 wherein the hydrocarbon comprises isobutane.
Claim 10
Dependent Claim
16 words
The process of claim 1 wherein the oxide is exposed on a surface of the substrate.
Claim 11
Dependent Claim
33 words
The process of claim 1 wherein the amount of hydrocarbon in the gas is effective to increase the selectivity of etching of the photoresist relative to the oxide to at least five hundred.
Claim 12
Dependent Claim
116 words
A process for removing photoresist from a substrate comprising a. providing a substrate having photoresist and oxide: b. forminig reactive species by generating a plasma of a gas comprising an oxidizing gas, a halogen-containing compound, and less than about five percent hydrocarbon under conditions capable of causing undesired etching of the oxide in the absence of the hydrocarbon; c. exposing the substrate to reactive species from the plasma; d. removing at least a portion of the photoresist from the substrate; and e. maintaining the flow of the hydrocarbon such that the selectivity of etching of the photoresist relative to the oxide is substantially increased over the selectivity that would exist in the absence of the hydrocarbon.
Claim 13
Dependent Claim
116 words
A process for removing photoresist from a substrate comprising a. providing a substrate having photoresist and oxide: b. forminig reactive species by generating a plasma of a gas comprising an oxidizing gas, a halogen-containing compound, and less than about five percent hydrocarbon under conditions capable of causing undesired etching of the oxide in the absence of the hydrocarbon; c. exposing the substrate to reactive species from the plasma; d. removing at least a portion of the photoresist from the substrate; and e. maintaining the flow of the hydrocarbon such that the selectivity of etching of the photoresist relative to the oxide is substantially increased over the selectivity that would exist in the absence of the hydrocarbon.
Claim 14
Dependent Claim
14 words
The process of claim 11 wherein the gas that releases hydrogen comprises an alkane.
Claim 15
Dependent Claim
69 words
The process of claim 1 wherein the step of forming reactive species further comprises the step of maintaining a low energy plasma such that the ions formed from the hydrocarbon include intermediate species containing both hydrogen and carbon; and wherein the step of exposing the surface of the silicon wafer further comprises the step of exposing the surface of the wafer to at least some of the intermediate species.
Claim 16
Dependent Claim
25 words
The process of claim 13 wherein the step of maintaining a low energy plasma further comprises the step of inductively coupling power into the plasma.
Claim 17
Dependent Claim
27 words
The process of claim 14 wherein the step of maintaining a low energy plasma further comprises the step of shielding the plasma with a split Faraday shield.
Claim 18
Dependent Claim
19 words
The process of claim 1, wherein the selectivity of the photoresist relative to the oxide is greater than 1000.
Claim 19
Dependent Claim
30 words
The process of claim 1 wherein the selectivity of the photoresist relative to the oxide is more than twice the selectivity that would exist in the absence of the hydrocarbon.
Claim 20
Dependent Claim
17 words
The process of claim 1 wherein the flow rate of the oxygen is greater than 1,000 SCCM.
Claim 21
Dependent Claim
16 words
The process of claim 1 wherein the flow rate of oxygen is greater than 2,000 SCCM.
Claim 22
Dependent Claim
26 words
The process of claim 1 wherein the flow rate of the hydrocarbon is less than about five percent of the flow rate of the oxidizing gas.
Claim 23
Dependent Claim
26 words
The process of claim 1 wherein the flow rate of the hydrocarbon is less than about one percent of the flow rate of the oxidizing gas.
Claim 24
Dependent Claim
27 words
The process of claim 1 wherein the flow rate of the halogen-containing compound is less than about five percent of the flow rate of the oxidizing gas.
Claim 25
Dependent Claim
26 words
The process of claim 1 further comprising the step of maintaining the temperature of a support for the wafer at substantially less than 150 degrees Celsius.
Claim 26
Dependent Claim
26 words
The process of claim 1 further comprising the step of maintaining the temperature of a support for the wafer at less than about 75 degrees Celsius.
Claim 27
Dependent Claim
27 words
The process of claim 11 wherein the step of forming reactive species by generating a plasma further comprises the step of inductively coupling power into the plasma.
Claim 28
Dependent Claim
19 words
The process of claim 11 wherein the selectivity of the photoresist relative to the oxide is greater than 1000.
Claim 29
Dependent Claim
30 words
The process of claim 11, wherein the selectivity of the photoresist relative to the oxide is more than twice the selectivity that would exist in the absence of the hydrocarbon.
Claim 30
Dependent Claim
17 words
The process of claim 11 wherein the flow rate of the oxygen is greater than 1,000 SCCM.
Claim 31
Dependent Claim
26 words
The process of claim 11 wherein the flow rate of the hydrocarbon is less than about one percent of the flow rate of the oxidizing gas.
Claim 32
Dependent Claim
26 words
The process of claim 11 further comprising the step of maintaining the temperature of a support for the wafer at substantially less than 150 degrees Celsius.
Claim 33
Dependent Claim
13 words
The process of claim 11 wherein the hydrocarbon contains only hydrogen and carbon.
Claim 34
Dependent Claim
10 words
The process of claim 11, wherein the hydrocarbon comprises isobutane.
Claim 35
Dependent Claim
118 words
A process for removing photoresist from a substrate comprising a. providing a substrate having photoresist and oxide; b. forming reactive species by generating a plasma of a gas comprising an oxidizing gas, a halogen-containing compound, and a hydrocarbon having at least three carbon atoms under conditions capable of causing undesired etching of the oxide in the absence of the hydrocarbon; c. exposing the substrate to reactive species from the plasma; d. removing at least a portion of the photoresist from the substrate; and e. maintaining the flow of the hydrocarbon such that the selectivity of etching of the photoresist relative to the oxide is substantially increased over the selectivity that would exist in the absence of the hydrocarbon.
Claim 36
Dependent Claim
118 words
A process for removing photoresist from a substrate comprising a. providing a substrate having photoresist and oxide; b. forming reactive species by generating a plasma of a gas comprising an oxidizing gas, a halogen-containing compound, and a hydrocarbon having at least three carbon atoms under conditions capable of causing undesired etching of the oxide in the absence of the hydrocarbon; c. exposing the substrate to reactive species from the plasma; d. removing at least a portion of the photoresist from the substrate; and e. maintaining the flow of the hydrocarbon such that the selectivity of etching of the photoresist relative to the oxide is substantially increased over the selectivity that would exist in the absence of the hydrocarbon.
Claim 37
Dependent Claim
52 words
The process of claim 33 wherein the step of forming reactive species by generating a plasma further comprises the step of forming ions; and wherein the step of exposing the substrate to reactive species from the plasma further comprises the step of exposing the photoresist to at least some of the ions.
Claim 38
Dependent Claim
26 words
The process of claim 33 wherein the flow rate of the hydrocarbon is less than about five percent of the flow rate of the oxidizing gas.
Claim 39
Dependent Claim
13 words
The process of claim 33 wherein the hydrocarbon contains only hydrogen and carbon.
Claim 40
Dependent Claim
10 words
The process of claim 33 wherein the hydrocarbon comprises isobutane.
Claim 41
Dependent Claim
26 words
The process of claim 34 wherein the flow rate of the hydrocarbon is less than about five percent of the flow rate of the oxidizing gas.
Claim 42
Dependent Claim
24 words
The process of claim 1 further comprising the step of etching the photoresist at a rate of at least about 0.3 microns per minute.
Claim 43
Dependent Claim
24 words
The process of claim 11 further comprising the step of etching the photoresist at a rate of at least about 0.3 microns per minute.
Claim 44
Dependent Claim
24 words
The process of claim 33 further comprising the step of etching the photoresist at a rate of at least about 0.3 microns per minute.
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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) | 2001-10-19 | 2002-04-20 | 2002-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-19 | 2006-04-20 | 2006-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-19 | 2010-04-20 | 2010-10-20 | $7700.00 | Window Closed / Lapsed |