A Balanced-SeeSaw MEMS swing probe for vertical profilometry of deep micro structures

An actuator-integrated MEMS needle probe is improved to measure vertical surface profile of narrow and deep test structures such as microholes and trenches. A newly developed surface scanning method, called ¿swing probing¿, can reduce the measurable feature size by factor of up to eight (i.e. from 40 ¿m down to 5 ¿m for 50¿m-deep trenches, and down to 25 ¿m for 1 mm-deep ones) as compared to traditional ¿slide probing¿. The improvement is due to the new ¿Balanced-SeeSaw¿ probe design that guarantees rotational movement without wobbling as well as sensitivity increase. Since the design is highly scalable, the probe can further reduce target feature size as well as measurement resolution thus may enlarge the application field of such surface quality assessment technology to MEMS process test structure monitoring.