| US 7,547,636 B2 | ||
| Pulsed ultra-high aspect ratio dielectric etch | ||
| Kyeong-Koo Chi, Pleasanton, Calif. (US); and Erik A. Edelberg, Castro Valley, Calif. (US) | ||
| Assigned to Lam Research Corporation, Fremont, Calif. (US) | ||
| Filed on Feb. 05, 2007, as Appl. No. 11/671,342. | ||
| Prior Publication US 2008/0188082 A1, Aug. 07, 2008 | ||
| Int. Cl. H01L 21/302 (2006.01) | ||
| U.S. Cl. 438—714 [438/710; 438/723; 438/724; 438/725; 216/67; 216/68; 216/72; 216/74; 216/81] | 18 Claims |
| 1. A method for etching an ultra high aspect ratio feature dielectric layer through a carbon based mask in an etch chamber,
comprising:
a selective etching the dielectric layer with respect to the carbon based mask, wherein the selective etching provides a net
deposition of a fluorocarbon based polymer on the carbon based mask;
stopping the selective etch; and
a subsequent selective etching the dielectric layer with respect to the carbon based mask, comprising:
providing a flow of an etch gas, comprising a fluorocarbon containing molecule and an oxygen containing molecule to the etch
chamber;
providing a pulsed bias RF signal; and
providing an energizing RF signal.
|