Abstract
One critical issue in advanced semiconductor processing is to have adequate dopant activation in the polycrystalline silicon (poly-Si) gate to minimize carrier depletion at the gate/gate oxide interface (poly-depletion). We demonstrate a novel technique, using laser thermal processing, to form super-doped n(+)-poly-Si gates on ultrathin gate oxides. The results indicate that the poly-depletion effect in n-channel metal-oxide-semiconductor (NMOS) devices can be significantly reduced if the entire as-deposited amorphous silicon gate melts upon laser irradiation. Time-dependent dielectric breakdown studies show that the gate oxide reliability is not degraded even after laser processing at a high fluence. (C) 2003 The Electrochemical Society.