Self-aligned silicon MOS device

摘要

An MOS transistor having relatively low parasitic capacitances is achieved by forming a dielectrically isolated mesa on a monocrystalline substrate. Such mesa includes a polycrystalline silicon region that serves as a gate region and an oxide layer that serves as a gate oxide. Subsequently, such mesa is made to sit on a platform, arising from the silicon substrate and surrounded by a sea of silicon dioxide originally at the level of the bottom of the mesa. The level of this sea is lowered to expose opposed sides of the platform to which is grown separate regions of lateral epitaxial silicon that serve as the source and drain of the transistor.