Investigation of stress effects on the direct current characteristics of GaAs metal-semiconductor field-effect transistors through the use of externally applied loads

This letter describes an experimental investigation of the effects of mechanical stress on the direct current (dc) electrical parameters in GaAs metal-semiconductor field-effect transistors, with the aim of separating out those effects which are direct manifestations of residual stresses in the completed device (e.g., piezoelectric effects) from stress effects which manifest themselves during the device processing (e.g., stress-enhanced diffusion during implant annealing). This study extends previous work by examining individual transistors under both tensile and compressive loads. Systematic yet nonmonotomic variations in the dc parameters observed in several devices also suggest the possibility of defect generation in the device structures, even at relatively low bulk stresses.