US 12,032,298 B2
Measurement tool and method for lithography masks
Yoshihiro Tezuka, Tsukuba (JP); Adam Seeger, Palo Alto, CA (US); and Ping Qu, San Jose, CA (US)
Assigned to Intel Corporation, Santa Clara, CA (US)
Filed by Intel Corporation, Santa Clara, CA (US)
Filed on Sep. 23, 2021, as Appl. No. 17/482,507.
Prior Publication US 2022/0011679 A1, Jan. 13, 2022
Int. Cl. G03F 7/00 (2006.01); G01N 21/956 (2006.01)
CPC G03F 7/70608 (2013.01) [G01N 21/956 (2013.01); G03F 7/70716 (2013.01); G03F 7/7085 (2013.01); G01N 2021/95676 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A measurement tool comprising:
a source assembly configured to generate a high power extreme ultraviolet (EUV) light beam;
a detector assembly comprising a projection optics system and a charge-coupled device (CCD) camera;
a stage control system;
a stage for supporting a patterned mask, the pattern mask comprising a plurality of predetermined test sites;
a processor configured to:
determine a site specific best focus plane for each of the plurality of predetermined test sites on the patterned mask based on best focus planes measurements for pre-selected calibration sites using a single scan that provides a continuous image output from the test site; and
generate instructions to move the stage to the best focus plane for each of the plurality of predetermined test sites on the patterned mask to generate critical dimension data.