US6013582A
Expired / Lapsed
US
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Method for etching silicon oxynitride and inorganic antireflection coatings
Assignee: Applied Materials Inc
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Filing: 1997-12-08
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Granted: 2000-01-11
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Expires: 2017-12-08
Abstract
Abstract The present disclosure pertains to a method for plasma etching a semiconductor patterning stack. The patterning stack includes at least one layer comprising either a dielectric-comprising antireflective material or an oxygen-comprising material. In many instances the dielectric-comprising antireflective material will be an oxygen-comprising material, but it need not be limited to such materials. In one preferred embodiment of the method, the chemistry enables the plasma etching of both a layer of the dielectric-comprising antireflective material or oxygen-comprising material and an adjacent or underlying layer of material. In another preferred embodiment of the method, the layer of dielectric-comprising antireflective material or oxygen-comprising material is etched using one chemistry, while the adjacent or underlying layer is etched using another chemistry, but in the same process chamber. Of particular interest is silicon oxynitride, an oxygen-comprising material which functions as an antireflective material. A preferred embodiment of the method provides for the use of a source of carbon and an appropriate halogen-comprising plasma, to achieve selective etch of one oxygen-containing material compared with another material which contains a more limited amount of oxygen.
Inventors
- 👤 Pavel Ionov
- 👤 Sung Ho Kim
- 👤 Dean Li
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:22
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10P50/71; H10P76/00; H10P76/20; H10P76/204; H10P76/2041; H10P76/2043
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
70 words
A method for improving selectivity in plasma etching of a semiconductor film stack including at least one oxygen-comprising layer, said method comprising: using an etchant gas including at least one compound comprising fluorine and carbon, wherein the ratio of fluorine to carbon in said etchant gas is adjusted to provide selectivity of etching among materials in said film stack on the basis of the relative oxygen content of said materials.
Claim 2
Independent Claim
70 words
A method for improving selectivity in plasma etching of a semiconductor film stack including at least one oxygen-comprising layer, said method comprising: using an etchant gas including at least one compound comprising fluorine and carbon, wherein the ratio of fluorine to carbon in said etchant gas is adjusted to provide selectivity of etching among materials in said film stack on the basis of the relative oxygen content of said materials.
Claim 3
Dependent Claim
67 words
The method of claim 1, wherein said etchant gas forms a fluorine-comprising polymer or species which deposits on exposed surfaces within said film stack in an amount which is proportional to the oxygen content present on said surfaces, whereby the etch rate of said surfaces containing a lower atomic percentage of oxygen is lower than the etch rate of surfaces containing a higher atomic percentage of oxygen.
Claim 4
Dependent Claim
18 words
The method of claim 1 or claim 2, wherein said at least one oxygen-comprising layer is silicon oxynitride.
Claim 5
Dependent Claim
41 words
The method of claim 3, wherein said silicon oxynitride is SiO x N y H z , where x ranges from 0 to about 2, y ranges from about 0 to about 1, and z ranges from 0 to about 1.
Claim 6
Dependent Claim
17 words
The method of claim 4, wherein x, y, and z range between about 0.2 and about 0.5.
Claim 7
Dependent Claim
16 words
The method of claim 3, wherein an exposed surface adjacent said silicon oxynitride comprises a photoresist.
Claim 8
Dependent Claim
12 words
The method of claim 6, wherein said photoresist is a DUV photoresist.
Claim 9
Dependent Claim
43 words
The method of claim 1, or claim 2, wherein said plasma etching is carried out in an apparatus which enables independent control of a plasma density and of a source of bias power which affects an ion bombardment energy of a substrate surface.
Claim 10
Dependent Claim
40 words
The method of claim 3, wherein said plasma etching is carried out in an apparatus which enables independent control of a plasma density and of a source of bias power which affects an ion bombardment energy of a substrate surface.
Claim 11
Dependent Claim
40 words
The method of claim 8, wherein plasma-generated ions are directed toward a surface of said oxygen-comprising layer in a manner which activates oxygen contained on said layer surface to react with carbon adjacent to or in contact with said surface.
Claim 12
Dependent Claim
37 words
The method of claim 2, wherein said etchant gas includes an assisting gas which is used to increase an etching rate by controlling the rate of deposition of said fluorine-comprising polymer or species on said stack surface.
Claim 13
Dependent Claim
33 words
The method of claim 11, wherein said assisting gas is selected from the group consisting of Cl 2 , F 2 , HF, HCl, NF 3 , SF 6 , and combinations thereof.
Claim 14
Dependent Claim
43 words
The method of claim 11, wherein said etchant gas compound comprising fluorine and carbon is selected from the group consisting of CHF 3 , CF 4 , CF 3 Cl, C 2 F 4 , C 2 F 6 , and combinations thereof.
Claim 15
Dependent Claim
19 words
The method of claim 13, wherein said compound is CHF 3 , CF 4 , or a combination thereof.
Claim 16
Dependent Claim
33 words
The method of claim 13, wherein said assisting gas is selected from the group consisting of Cl 2 , F 2 , HF, HCl, NF 3 , SF 6 , and combinations thereof.
Claim 17
Dependent Claim
31 words
The method of claim 15, wherein said assisting gas is chlorine, and wherein an atomic ratio of fluorine to chlorine in said etchant gas ranges between about 3:1 and about 1:2.
Claim 18
Dependent Claim
25 words
The method of claim 1 or claim 2, wherein said oxygen-comprising layer and a metal-comprising layer are both etched using a single etchant gas mixture.
Claim 19
Dependent Claim
24 words
The method of claim 1 or claim 2, wherein said oxygen-comprising layer and said metal-comprising layer are both etched in a single processing chamber.
Claim 20
Dependent Claim
15 words
The method of claim 2, wherein said etchant gas mixture does not contain free oxygen.
Claim 21
Independent Claim
52 words
A method for plasma etching a silicon oxynitride-comprising layer in a semiconductor film stack, said method comprising: using an etchant gas mixture comprising chlorine and at least one compound comprising fluorine and carbon, wherein the atomic ratio of fluorine to chlorine in said etchant gas ranges between about 3:1 and about 1:2.
Claim 22
Independent Claim
52 words
A method for plasma etching a silicon oxynitride-comprising layer in a semiconductor film stack, said method comprising: using an etchant gas mixture comprising chlorine and at least one compound comprising fluorine and carbon, wherein the atomic ratio of fluorine to chlorine in said etchant gas ranges between about 3:1 and about 1:2.
Claim 23
Dependent Claim
48 words
The method of claim 20, wherein said etchant gas forms a fluorine-comprising polymer or species which deposits on exposed surfaces adjacent to said silicon oxynitride-comprising layer in an amount sufficient to reduce the etch rate of said adjacent material while permitting the etching of said silicon oxynitride-comprising layer.
Claim 24
Dependent Claim
20 words
The method of claim 21, wherein a material having an exposed surface adjacent said silicon oxynitride-comprising layer comprises a photoresist.
Claim 25
Dependent Claim
12 words
The method of claim 22, wherein said photoresist is a DUV photoresist.
Claim 26
Dependent Claim
46 words
The method of claim 21, or claim 22, or claim 23, wherein said plasma etching is carried out in an apparatus which enables independent control of a plasma density and of a source of bias power which affects an ion bombardment energy of a substrate surface.
Claim 27
Dependent Claim
43 words
The method of claim 20, wherein said etchant gas compound comprising fluorine and carbon is selected from the group consisting of CHF 3 , CF 4 , CF 3 Cl, C 2 F 4 , C 2 F 6 , and combinations thereof.
Claim 28
Dependent Claim
63 words
The method of claim 25, wherein said etchant gas includes an assisting gas which is used to increase the rate of etching by controlling the rate of deposition of said fluorine-comprising polymer or species on said stack surface, wherein said assisting gas is selected from the group consisting of F 2 , HF, HCl, NF 3 , SF 6 , and combinations thereof.
Claim 29
Dependent Claim
25 words
The method of claim 20 or claim 21, wherein said oxygen-comprising layer and a metal-comprising layer are both etched using a single etchant gas mixture.
Claim 30
Dependent Claim
24 words
The method of claim 20 or claim 21, wherein said oxygen-comprising layer and said metal-comprising layer are both etched in a single processing chamber.
Claim 31
Dependent Claim
15 words
The method of claim 21, wherein said etchant gas mixture does not contain free oxygen.
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