| US 7,572,734 B2 | ||
| Etch depth control for dual damascene fabrication process | ||
| Mehul Naik, San Jose, Calif. (US); Suketu A. Parikh, San Jose, Calif. (US); and Michael D. Armacost, San Jose, Calif. (US) | ||
| Assigned to Applied Materials, Inc., Santa Clara, Calif. (US) | ||
| Filed on Oct. 24, 2007, as Appl. No. 11/877,964. | ||
| Claims priority of provisional application 60/863324, filed on Oct. 27, 2006. | ||
| Prior Publication US 2008/0102638 A1, May 01, 2008 | ||
| Int. Cl. H01L 21/311 (2006.01) | ||
| U.S. Cl. 438—702 [438/714; 257/758; 257/E21.249] | 20 Claims |
| 1. A method of forming a dual damascene structure on the surface of a substrate having areas of high feature density and areas
of low feature density, comprising:
depositing a dopant material layer into a dielectric film stack deposited on the surface of the substrate;
depositing a top layer over the dielectric film stack;
performing via lithography and via etch into the dielectric film stack;
performing trench lithography on the top layer to form a trench pattern; and
performing a trench etch process, wherein trenches are etched slower in areas of high feature density than in areas of low
feature density until the dopant material layer is reached, after which trenches are etched faster in areas of high feature
density than in areas of low feature density.
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