Method of making semiconductor devices having two-layer gate structure

摘要

The present invention includes a method of forming semiconductor oxide layers and, in particular, gate oxide layers, in MOS semiconductor devices formed on silicon substrates. The method includes the steps of forming a first silicon oxide sublayer on the silicon substrate in an atmosphere including primarily oxygen, and forming a second silicon oxide sublayer over the first sublayer in an atmosphere including primarily nitrous oxide (N2O). Preferably, the first and second sublayers represent 80 percent and 20 percent, respectively, of the silicon oxide layer.