US 6,982,221 B1 | ||
Method of forming 2/3F pitch high density line array | ||
Sheng Teng Hsu, Camas, Wash. (US) | ||
Assigned to Sharp Laboratories of America, Inc., Camas, Wash. (US) | ||
Filed on Jun. 10, 2005, as Appl. No. 11/149,884. | ||
Int. Cl. H01L 21/4763 (2006.01); H01L 21/20 (2006.01) |
U.S. Cl. 438—618 | 9 Claims |
1. A method of forming a ⅔F pitch high density line array, where F is the minimum line width of a photolithographic process
used to accomplish the method of the invention; comprising:
preparing a wafer;
depositing a conductive material on the wafer to function as contact pads and electrodes;
depositing a layer of sacrificial material on the conductive material;
applying and patterning a layer of photoresist on the sacrificial material;
etching the sacrificial material to form a placeholder having width and space of F;
depositing sidewall spacer material hard mask to a thickness of about ⅓F on the placeholder;
applying and patterning a layer of photoresist on the hard mask;
anisotropically etching the hard mask material;
depositing a layer of silicon oxide and smoothing the silicon oxide by CMP;
selectively removing the placeholder;
depositing a second sidewall spacer layer to a thickness of about ⅓F;
depositing another hard mask layer and smoothing the other hard mask layer by CMP;
etching the silicon oxide and conductive material using the other hard mask lines as a pattern;
applying and patterning a layer of photoresist;
etching to form interconnect lines and contact pads; and
selectively etching any remaining hard mask material to expose lines and contact pads.
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