| 摘要 |
A method of manufacturing an SOI (silicon on insulator) wafer includes the step of selective anisotropic etching to form, in the substrate, trenches which extend to a predetermined depth from a major surface of the substrate and between which pillar portions of the substrate are defined. The method further includes the step of selective isotropic etching to enlarge the trenches, starting at a predetermined distance from the major surface, thus reducing the thicknesses of the pillar portions of the substrate between adjacent trenches. Also, the method includes the steps of selective oxidation to convert the pillar portions of reduced thickness of the substrate into silicon dioxide and to fill the trenches with silicon dioxide, starting substantially from the predetermined distance, and epitaxial growth of a silicon layer on the major surface of the substrate. The method permits more freedom in the selection of the dimensional ratios between the trenches and the pillars and thus enables the necessary crystallographic quality of the epitaxial layer to be achieved, ensuring a continuous buried oxide layer.
|
