Method for etching silicon oxynitride and inorganic antireflection coatings
First Claim
1. 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.
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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.
107 Citations
29 Claims
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1. 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.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. 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. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29)
- 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;
Specification