LOCOS-INDUCED STRESS EFFECTS ON THIN-FILM SOI DEVICES

LOCOS-induced stress effects on thin-film SOI devices are investigated , We shaw that as the field oxide thickness increases, degradation (en hancement) of nMOSFET's (pMOSFET's) I-V characteristics becomes increa singly pronounced. The total degradation or enhancement of I-V charact eristics can reach similar to 40% of drive current for devices under c ertain processing condition, Estimated stress results using four-point bending measurement show that the stress level on the silicon film is of order 1200 MPa for devices with similar to 40% of I-V degradation/ enhancement. We attribute the stress phenomenon to the volumetric expa nsion of held oxide during the LOCOS process.