Method and apparatus for STI using passivation material for trench bottom liner

摘要

A silicon-on-insulator semiconductor device, including a silicon-on-insulator wafer having a silicon active layer, a dielectric isolation layer a silicon substrate, and at least one isolation trench defining an active island in the silicon active layer, in which the silicon active layer is formed on the dielectric insulation layer and the dielectric insulation layer is formed on the silicon substrate, in which the at least one isolation trench includes a layer of a passivating insulator in a lower portion of the isolation trench and in contact with the dielectric insulation layer. The passivating insulator prevents formation of a bird's beak between the silicon active layer and the dielectric insulation layer during subsequent fabrication of the isolation trench.