Timothy Thuan Tran

US Patent:

7479458, Jan 20, 2009

Filed:

Dec 15, 2005

Appl. No.:

11/305369

Inventors:

Guang-Yaw Hwang - Hsin-Shi, TW
Thomas Nguyen - Fremont CA, US
Timothy Tran - Fremont CA, US
Yu-Wei Yang - Hsin-Shi, TW

Assignee:

Lam Research Corporation - Fremont CA

International Classification:

H01L 21/302

US Classification:

438714, 438725, 438740, 216 67

Abstract:

A method for etching a barrier material on a semiconductor substrate is disclosed. The method includes placing the substrate in a plasma processing chamber of the plasma processing system, wherein the substrate includes the barrier material and a low-k material, and wherein the barrier material and a low-k material are configured to be exposed to a plasma. The method also includes flowing an etchant gas mixture, including CHF from about 4% to about 8% of a plasma gas flow, into the plasma processing chamber, wherein the etchant gas mixture is configured to etch the barrier material at a first etch rate, the etchant gas mixture is configured to etch the low-k material at a second etch rate, wherein the first etch rate is substantially greater than the second etch rate. The method further includes striking a plasma from the etchant source gas; and etching the barrier layer and the low-k layer.