PHOTON-ENERGY DISTRIBUTION OF HOT-CARRIER PHOTOEMISSION FROM LOCOS AND TRENCH-ISOLATED MOSFETS

Two-dimensional (2-D) photon-energy distributions emitted from hot-car riers in LOCOS and trench-isolated CMOS devices with a narrow channel width of about 10 mum are measured. The 2-D photoemission images show different characteristics depending on the photon energy. Relatively l arge spatial fluctuations of normalized photoemission-intensity profil es for each photon energy are observed, while all the profiles show si milar trapezoidal shapes along the channel width direction. Average el ectron temperatures are about 3700 and 3500 K for n - and p -MOSFETs, respectively, independently of the isolation technologies. Quite chara cteristic photoemission profiles and 2-D images are observed in trench -isolated n-MOSFETs after high bias-voltage stress.