Tungsten barrier and seed for copper filled TSV
AssigneeNovellus Systems, Inc.
InventorsMichal Danek, Tom Mountsier, Jonathan Reid, Juwen Gao, Aaron Fellis
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Abstract
Apparatus and methods for filling through silicon vias (TSV's) with copper having an intervening tungsten layer between the copper plug and the silicon are disclosed. Methods are useful for Damascene processing, with or without a TSV feature. The tungsten layer serves as a diffusion barrier, a seed layer for copper electrofill and a means of reducing CTE-induced stresses between copper and silicon. Adhesion of the tungsten layer to the silicon and of the copper layer to the tungsten is described.
Claims25
A semiconductor processing method comprising:
- (i) receiving a semiconductor wafer comprising through silicon via (TSV) holes;
- (ii) depositing an adhesion layer on an exposed surface of the received semiconductor wafer;
- (iii) depositing a tungsten seed layer on the adhesion layer;
- and
- (iv) electroplating copper on the tungsten seed layer to deposit copper at least within the TSV holes, wherein prior to the copper electroplating, the tungsten seed layer is electrically biased and is exposed to an acidic medium, the acidic medium being substantially free from copper ions.
A semiconductor processing method comprising:
- (i) providing a semiconductor wafer comprising one or more TSV holes;
- (ii) depositing an adhesion layer between about 10 Å and about 100 Å thick on the semiconductor wafer;
- (iii) depositing a tungsten seed layer between about 500 Å and about 1000 Å thick on the adhesion layer;
- and
- (iv) electroplating bulk fill copper on the tungsten seed layer until the one or more TSV holes are filled with copper, wherein prior to the copper electroplating, the tungsten seed layer is electrically biased and is exposed to an acidic medium, the acidic medium being substantially free from copper ions.
Dependencies are inferred from the claim text.