Elimination of resist footing on tera hardmask
AssigneeInfineon Technologies North America Corp.
InventorXiaochun Linda Chen
Life of this patent
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Abstract
A process of eliminating resist footing on a hardmask when preparing a semiconductor wafer stack, comprising: a) depositing a layer of hardmask material on a substrate; b) subjecting the hardmask to oxygen under conditions sufficient to produce an oxide cap layer and provide a hardmask/oxide cap layer with a substrate reflectivity below 0.8%; c) forming a layer of SiO2 on the hardmask/oxide cap layer; d) forming a layer of photoresist on the layer of SiO2; e) patterning and developing the layer of photoresist by exposing photoresist; and f) etching exposed portions of the layer of hardmask/oxide cap layer/SiO2 layer to obtain a semiconductor wafer stack with no standing waves and free from resist footing.
Claims22
A process of eliminating resist footing on a hardmask when preparing a semiconductor wafer stack, comprising:
- a) depositing a layer of hardmask material on a substrate;
- b) subjecting the hardmask to oxygen under conditions sufficient to produce an oxide cap layer and provide a hardmask/oxide cap layer with a substrate reflectivity below 0.8%;
- c) forming a layer of SiO2 on the hardmask/oxide cap layer;
- d) forming a layer of photoresist on the layer of SiO2;
- e) patterning and developing the layer of photoresist by exposing photoresist;
- and
- f) etching exposed portions of the layer of hardmask/oxide cap layer/SiO2 layer to obtain a semiconductor wafer stack with no standing waves and free from resist footing.
The process of claim 4 wherein said photoresist of step d) is a single layer resist (SLR).
A semiconductor wafer stack having a DT level and characterized by no standing waves, a substrate reflectivity below about 0.8%, and no resist footing, said stack comprising a SiO2 blocking layer disposed between a hardmask/oxide cap layer and a patterned and developed resist layer.
Dependencies are inferred from the claim text.