The Small Business Innovation Research (SBIR) Phase I project will develop a novel infrared measurement technique for determining the thickness of ultra-thin (0 to 200 microns) and patterned silicon wafers, and the depth of etched features (maximum trench depth of 150 microns) in micro electro-mechanical systems (MEMS). The proposed instrument is a chromatic confocal sensor (spreads a focused spot along the axial direction according to color, or wavelength, of the light) operating in the near infrared spectrum, where silicon is transparent.
With the advent of ultra-thin wafers, the present technology of capacitance testing to gage the wafers is no longer adequate. The proposed instrument, therefore, will improve the accuracy of measurements needed in the silicon microelectronics and MEMS industries. This measurement technique also has the potential to reduce the cost of silicon based microelectronics.