High quality SOI material produced using isolated silicon epitaxy

Abstract

Summary form only given. High-quality SOI layers have been produced using isolated silicon epitaxy (ISE) technology, which is based on lateral epitaxy by seeded solidification (LESS) and zone melting recrystallization (ZMR). ISE wafers are manufactured in production volumes and have consistently demonstrated low-defect density (<10/sup 6//cm/sup 2/), high-quality surfaces (haze less than 2000 p.p.m.), no protrusions, and low warpage (less than 80 mu m). Single-crystal silicon films have been obtained with excellent crystalline properties as compared to other SOI techniques. ISE wafers have no large grain boundaries or subboundaries. Low densities of isolated threading dislocations with occasional defect clusters have been observed. The high quality of the interface between the oxide and silicon thin film and the interface between the oxide and the substrate has been demonstrated. Electrical characterization of ISE films indicates low background dopant density (<10/sup 15//cm/sup 3/) and low oxide charge density at the Si-film-buried oxide interface (<10/sup 11//cm/sup 2/). These measurements were performed on depletion-mode MOS transistors. Channel leakage currents were less than 0.1 pA/ mu m on enhancement-mode MOS transistors made using a mesa technique. Carrier mobilities were near bulk values. In lateral pn diodes, the junction leakage was less than 0.3 mu A/cm/sup 2/ with a 5-V reverse bias applied. DLTS measurements showed no detectable levels of electrically active traps.<>