Chemical mechanical polishing slurry, its preparation method and use for the same
AssigneeEpoch Material Co., Ltd.
InventorsHui-Fang HOU, Wen Cheng LIU, Yen-Liang CHEN, Jui-Ching CHEN
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Abstract
A chemical mechanical polishing slurry for polishing a copper layer without excessively or destructively polishing a barrier layer beneath the copper layer is disclosed and includes an acid, a surfactant, and a silica sol having silica polishing particles that are surface modified with a surface charge modifier and that have potassium ions attached thereto. A method for preparing the chemical mechanical polishing slurry and a chemical mechanical polishing method using the chemical mechanical polishing slurry are also disclosed.
Claims6
A chemical mechanical polishing method, comprising the steps of:
- (a) contacting a wafer with a polishing pad;
- (b) supplying a chemical mechanical polishing slurry including a silica sol that contains silica polishing particles to the wafer and the polishing pad, the silica polishing particles being surface modified with a surface charge modifier and having potassium ions attached to the silica polishing particles;
- and (c) planarizing at least a portion of a surface of the wafer with the chemical mechanical polishing slurry.
A method for preparing a chemical mechanical polishing slurry that can polish a copper layer without excessively or destructively polishing a barrier layer beneath the copper layer, comprising the steps of:
- (a) decationizing a solution of a silicate through a cation exchanger to form silicic acid in the solution;
- and (b) alkalizing the silicic acid with potassium hydroxide or potassium water glass to form silica polishing particles that have potassium ions attached thereto.
Dependencies are inferred from the claim text.