Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
93 words
A method of etching a dielectric layer on a substrate, the method comprising the steps of: (a) placing the substrate in a process zone, the substrate comprising a dielectric layer having resist material thereon; (b) forming a plasma from process gas introduced into the process zone, the process gas comprising (i) fluorocarbon gas for etching the dielectric layer and forming passivating deposits on the substrate, (ii) carbon-oxygen gas to enhance formation of the passivating deposits, and (iii) nitrogen-containing gas for etching at least a portion of the passivating deposits formed on the substrate.
Claim 2
Dependent Claim
59 words
A method according to claim 1, wherein in step (b), the volumetric flow ratio of fluorocarbon:carbon-oxygen:nitrogen-containing gas is selected to obtain (i) an etching selectivity ratio for etching dielectric relative to resist of at least about 10:1, (ii) an etch rate microloading of less than about 10%, and (iii) a dielectric etch rate of at least about 100 nm/min.
Claim 3
Independent Claim
80 words
A method according to any one of the preceding claims, wherein in step (b), the volumetric flow ratio of fluorocarbon:carbon-oxygen:nitrogen-containing gas is selected to provide: (1) a rate of formation of passivating deposits that is approximately equal to the rate of removal of the passivating deposits; and (2) an etching selectivity ratio for etching dielectric relative to underlayer below the dielectric of at least about 20:1, where the underlayer comprises polysilicon, monocrystalline silicon, titanium silicide, diffusion barrier, or anti-reflective layers.
Claim 4
Dependent Claim
22 words
A method according to claim 1 is characterized in that the volumetric flow ratio of fluorocarbon:carbon-oxygen:nitrogen-containing gas is from 7:8:4 to 3:4:4.
Claim 5
Dependent Claim
22 words
A method according to claim 4 is characterized in that the volumetric flow ratio of fluorocarbon:carbon-oxygen:nitrogen-containing gas is from 6:7:4 to 4:5:4.
Claim 6
Dependent Claim
23 words
A method according to claim 1 is characterized in that volumetric flow of fluorocarbon gas to nitrogen gas is from 5:1 to 1:5.
Claim 7
Independent Claim
35 words
A method according to any one of the preceding claims, characterized in that the nitrogen-containing gas is absent fluorine, and comprises at least one of N 2 , N 2 O, or NO x .
Claim 8
Independent Claim
31 words
A method according to any one of the preceding claims is characterized in that flow rate of carbon-oxygen gas is less than or equal to the flow rate of fluorocarbon gas.
Claim 9
Independent Claim
31 words
A method according to any one of the preceding claims is characterized in that the fluorocarbon gas comprises (i) first fluorocarbon gas containing hydrogen, and (ii) second fluorocarbon gas absent hydrogen.
Claim 10
Dependent Claim
123 words
A method according to claim 9 is characterized in that: (1) the first fluorocarbon gas comprises at least one of CHF 3 , CH 3 F, C 2 HF 5 , CH 2 F 2 , or C 2 H 4 F 6 ; (2) the second fluorocarbon gas comprises at least one of CF 4 , C 2 F 6 , C 3 F 8 , C 4 F 8 , or C 4 F 10 ; (3) the flow rate of carbon-oxygen gas is less than or equal to the combined flow rates of the first and second fluorocarbon gases; or (4) the volumetric flow ratio of the first fluorocarbon gas to the second fluorocarbon gas is from 1:1 to 10:1.
Claim 11
Independent Claim
40 words
A method according to any one of the preceding claims is characterized in that the process gas comprises an inert gas for sputtering the substrate, the volumetric flow ratio of process gas to inert gas being from 3:1 to 1:2.
Claim 12
Independent Claim
34 words
A method according to any one of the preceding claims is characterized in that the process gas consists of CHF 3 , C 4 F 8 , CO, N 2 , and inert gas.
Claim 13
Dependent Claim
83 words
A method according to claim 12 is characterized in that (1) the volumetric flow ratio of CHF 3 to C 4 F 8 is from 1:1 to 10:1; (2) the ratio of the combined CHF 3 and C 4 F 8 flow rate to the N 2 flow rate is from 5:1 to 1:5; or (3) the flow rate of the carbon-oxygen gas is less than or equal to the combined flow rates of the CHF 3 and C 4 F 8 gases.