Method for the selective removal of high-k dielectrics
First Claim
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1. A method of removing an exposed portion of a high-k dielectric layer from a substrate, comprising:
- providing a substrate with a high-k dielectric layer;
wet etching with a final etching solution consisting essentially of water, a strong acid, an oxidizing agent, and a fluorine compound;
wherein the strong acid is not the same as the fluorine compound.
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Abstract
One aspect of the invention relates to a method of etching a high-k dielectric. The method involves removing an exposed portion of a high-k dielectric layer from a substrate by wet etching with a solution comprising water, a strong acid, an oxidizing agent, and a fluorine compound. The etching solution provides selectivity towards the high-k film against insulating materials and polysilicon and is therefore useful in manufacturing FETs.
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Citations
23 Claims
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1. A method of removing an exposed portion of a high-k dielectric layer from a substrate, comprising:
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providing a substrate with a high-k dielectric layer;
wet etching with a final etching solution consisting essentially of water, a strong acid, an oxidizing agent, and a fluorine compound;
wherein the strong acid is not the same as the fluorine compound. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
forming isolation regions;
forming a gate layer comprising a high-k dielectric;
forming a poly layer;
patterning the poly layer; and
patterning the gate layer;
whereinthe gate layer is patterned using a process according to claim 1.
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18. A method of etching high-k dielectric, comprising:
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providing high-k dielectric material;
etching with a first solution comprising a first strong acid to remove a bulk portion of the high-k dielectric;
etching with a second solution comprising water, a second strong acid, an oxidizing agent, and a fluorine compound to remove a second portion of the high-k dielectric;
wherein the first solution is not the same as the second solution, the second strong acid is not the same as the fluorine compound, and the second portion of the high-k dielectric is at least {fraction (1/10)}th the thickness of the bulk potion of the high-k dielectric. - View Dependent Claims (19, 20, 21, 22)
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23. A method of etching through a high-k dielectric layer of at least 1 nm thickness, comprising:
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providing a high-k dielectric layer of at least 1 nm thickness;
wet etching the layer with a solution comprising by volume at least about 25 percent sulfuric acid, at least about 1 percent hydrogen peroxide, and at least about 0.005 percent hydrofluoric acid.
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Specification