US 7,588,884 B2
Method for enhancing wafer alignment marks
Amanda Baer, Campbell, Calif. (US); Nian-Xiang Sun, Sunnyvale, Calif. (US); Sue Siyang Zhang, Saratoga, Calif. (US); and Yi Zheng, San Ramon, Calif. (US)
Assigned to Hitachi Global Storage Technologies Netherlands B.V., Amsterdam (Netherlands)
Filed on May 28, 2004, as Appl. No. 10/857,151.
Prior Publication US 2005/0266357 A1, Dec. 01, 2005
Int. Cl. G03F 1/00 (2006.01)
U.S. Cl. 430—324  [430/322; 430/315; 430/311] 19 Claims
 
1. A method of fabricating thin films on a wafer comprising the steps of:
depositing a first layer on the wafer which includes an alignment mark area;
depositing a transfer layer on the alignment mark area;
depositing a definition layer onto the transfer layer in the alignment mark area;
fabricating an alignment mark filled with a filler material above the transfer layer, fabricating the alignment mark further comprising forming a void in the definition layer for the alignment mark and filling the void with a filler material;
removing the filler material from the alignment mark exposing an underlying surface of the transfer layer; and
deepening the alignment mark by removing material from the underlying surface of the transfer layer.