Nondestructive evaluation of interfaces in bonded silicon-on-insulator structures using the picosecond ultrasonics technique

Picosecond ultrasonic techniques were used to generate and detect acoustic pulses in bonded silicon-on-insulator structures. By simulating the shapes and amplitudes of the acoustic echoes reflected from the Si-SiO2 interfaces, we can characterize the physical properties of the interfaces. We have observed that via a further thermal annealing process one can change the interface quality of a poorly bonded structure. © 1998 The Electrochemical Society, Inc.