Fracture toughness of polysilicon MEMS devices

Polysilicon fracture mechanics specimens have been fabricated using standar d microelectro-mechanical systems (MEMS) processing techniques, with charac teristic dimensions comparable to typical MEMS devices. These specimens are fully integrated with simultaneously fabricated electrostatic actuators th at are capable of providing sufficient force to ensure catastrophic crack p ropagation. Thus, the entire fracture experiment takes place on-chip, elimi nating the difficulties associated with attaching the specimen to an extern al loading source. The specimens incorporate atomically sharp cracks create d by indentation, and fracture is initiated using monotonic electrostatic l oading. The fracture toughness values are determined using finite element a nalysis (FEA) of the experimental data, and show a median value of 1.1 MPa m(1/2). (C) 2000 Elsevier Science S.A. All rights reserved.