| US 7,573,049 B2 | ||
| Wafer alignment method for dual beam system | ||
| Hiroyasu Kaga, Mito (Japan); Hiroyuki Suzuki, Hitachinaka (Japan); and Yutaka Hojyo, Hitachinaka (Japan) | ||
| Assigned to Hitachi High-Technologies Corporation, Tokyo (Japan) | ||
| Filed on Dec. 05, 2007, as Appl. No. 11/987,828. | ||
| Application 11/987828 is a continuation of application No. 11/258939, filed on Oct. 27, 2005, granted, now 7,323,697, filed on Jan. 29, 2008. | ||
| Claims priority of application No. 2004-314089 (JP), filed on Oct. 28, 2004. | ||
| Prior Publication US 2008/0174779 A1, Jul. 24, 2008 | ||
| Int. Cl. H01J 37/28 (2006.01) | ||
| U.S. Cl. 250—491.1 [250/306; 250/307; 250/309] | 8 Claims |
| 1. An alignment method in a charged particle beam apparatus including a stage capable of moving inside an XY plane and in
a Z axis direction perpendicular to said XY plane while holding a sample, a first column having an optical axis parallel to
said Z axis and a second column having an optical axis inclined to said Z axis, said method comprising steps of:
moving said stage inside the XY plane and positioning a first known mark on a sample to the visual field center of said first
column;
moving said stage by an offset between the visual field of said first column and the visual field of said second column;
observing said first known mark by said second column and determining a deviation amount from the visual field center;
determining a height deviation of the sample from a reference height on the basis of said deviation amount;
moving said stage by the height deviation in the Z axis direction and adjusting a sample surface provided with said first
known mark to said reference height and determining a position of said first known mark;
moving said stage inside the XY plane while fixing in said Z direction and positioning to a second known mark on the sample;
and
determining a position of the second known mark by said second column and achieving Die alignment.
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