Seiko Epson Corporation

The University of Tokyo

Santec Corporation

Santec Holdings Corporation

Keiji Isamoto

Mitsuhiro Yoda

Hiroshi Toshiyoshi

Atsushi Morosawa

Hiroyuki Itoh

A measurement apparatus for measuring a thickness of a semiconductor wafer includes: an optical system configured to perpendicularly irradiate a sample wafer and a reference wafer with light, and receive interference signals of the light reflected on front and back surfaces of the respective wafers; a signal processor configured to perform frequency analysis of the interference signals received by the optical system to obtain peak positions of a point spread function of the respective wafers; and a calculator configured to calculate a thickness 'tsample' of the sample wafer based on the peak position “x” of the sample wafer and the peak position “y” of the reference wafer obtained by the signal processor, and a thickness “treference” of the reference wafer.

Measurement method and measurement apparatus for measuring thickness of semiconductor wafer

An actuator that can be driven at a reduced voltage and manufactured with ease, and a method for manufacturing the same are provided. The actuator includes second supporting portionsandsecured to a supporting substratethrough a spacer, fixed portionsandsecured to the supporting substratewith no intervention of the spacer, fixed comb electrodesandintegrally formed the fixed portionsandand meshing with movable comb electrodesandin a spaced-apart relationship, and bridge portionsandfor connecting the fixed portionsandto the second supporting portionsand. The fixed portionsandare affixed to the supporting substratein a condition that they are deflected toward the supporting substratewith respect to the second supporting portionsandwhile bending the bridge portionsand, thereby initially deflecting the fixed comb electrodesandso as to be out of alignment with the movable comb electrodesandin a thickness direction of the supporting substrate

Actuator having deflected fixed comb electrodes and movable comb electrodes

Actuator having fixed and movable comb electrodes

Growing community of inventors

Aichi, Japan

Keiji Isamoto