Non-contact and non-destructive testing of silicon V-grooves: A nonmedical application of optical coherence tomography (OCT)

The paper reports a non-medical optical coherence tomography (OCT) application namely, the use of OCT to test a micro-electro-mechanical systems (MEMS) technology device. The OCT system used in this initial study combined a fibre Michelson interferometer and a 10 mW 1300 nm super luminescent diode (SLD). The system supported a measured depth resolution of 21 (mu)m as well as a transverse resolution of around 3 (mu)m. As a first demonstration, the depth and width of a MEMS Vshaped groove in silicon were measured to within 7% (6%) and 12% (14%) of the values determined by stylus contacting (standard microscopy) method, respectively. The OCT technique combines advantages of noncontact, non-invasive and non-destructive operation making it suitable for on-line precision measurement of V-shaped grooves in silicon.