Method to form a localized silicon-on-insulator structure

摘要

A semiconductor device and method of fabrication using LEGO (Lateral Epitaxial Growth over Oxide) for forming a SOI (Silicon On Insulator) structure (FIG. 1) having a localized buried dielectric layer (2). By patterning the buried dielectric layer, covered with a thin polysilicon layer by way of an epitaxial reactor a thick semiconductor layer (3) over the buried layer (2) is deposited. By rapid thermal annealing the polycrystalline overlayer is transformed into a single crystal layer (3). The buried oxide layer (2) provides a vertical dielectrical insulation, and deep diffused or trench regions (4, 5) provide lateral junction insulation. In this manner the SOI area (3) localized between the two deep diffused regions (4, 5) is fully insulated from the silicon substrate (1). This provides the following advantages: the process can be easily integrated in standard wafer fabrication equipment and processing techniques; the process is fully compatible with many existing technologies and their process flow; and low processing cost and low density defectivity should result. <IMAGE>