Session 6

[OPTM6-01(Invited)] Double-sided interferometer for precise thickness measurements

*Akiko Hirai¹, Youichi Bitou¹ (1. National Metrology Institute of Japan (NMIJ) / Advanced Industrial Science and Technology (AIST))

A double-sided interferometer (DSI) for non-contact SI-traceable absolute thickness measurement has been developed. The DSI uses the light beams reflected on both surfaces of a sample under measurement and doesn’t use the light beams transmitted through the sample. The expanded uncertainty of silicon wafer thickness measurement was evaluated as 20 nm (the coverage factor k = 2).