| US 7,491,647 B2 | ||
| Etch with striation control | ||
| S. M. Reza Sadjadi, Saratoga, Calif. (US); Peter Cirigliano, Sunnyvale, Calif. (US); Ji Soo Kim, Pleasanton, Calif. (US); Zhisong Huang, Fremont, Calif. (US); and Eric A. Hudson, Berkeley, Calif. (US) | ||
| Assigned to Lam Research Corporation, Fremont, Calif. (US) | ||
| Filed on Sep. 09, 2005, as Appl. No. 11/223,363. | ||
| Application 11/223363 is a continuation in part of application No. 11/076087, filed on Mar. 08, 2005, granted, now 7,241,683. | ||
| Prior Publication US 2006/0194439 A1, Aug. 31, 2006 | ||
| Int. Cl. H01L 21/311 (2006.01) | ||
| U.S. Cl. 438—696 [438/637; 438/942; 438/949; 257/E21.023] | 18 Claims |
| 1. A method for etching a feature in an etch layer, comprising:
forming a patterned photoresist mask over the etch layer with photoresist features with sidewalls wherein the sidewalls of
the photoresist features have striations forming peaks and valleys;
reducing the striations of the sidewalls of the photoresist features comprising at least one cycle, wherein each cycle comprises:
etching back peaks formed by the striations of the sidewalls of the photoresist features; and
depositing on the sidewalls of the photoresist features;
etching features into the etch layer through the photoresist features; and
removing the photoresist mask.
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