Reduced narrow-width effects in a scaled local oxidation of silicon process

Abstract

The reduction of narrow-width effects in VLSI transistors is of great importance if small-geometry devices are to be of real use in advanced circuits. These effects are caused by boron encroaching into the transistor channel from underneath the field isolation oxide. In this paper we describe the results of experiments to reduce this encroachment by the use of high-pressure oxidation. We show that the substitution of this process into a VLSI process flow, for the field oxidation step, allows the channel-stop implant dose to be significantly reduced (50%) without degradation of interdevice isolation.