Semiconductor substrate for a one-chip electronic device and related manufacturing method

摘要

A plurality of grooves, each having a depth of 10 mum or more and arranged adjacent to each other, are formed at a predetermined portion of a semiconductor substrate where a passive element is formed. Then, a thermal oxidation treatment is performed to let an oxide film grow from an inside surface of each groove so as to fill an inside space of the groove with a thermal oxide film thus grown and turn an entire portion intervening between adjacent grooves into a thermal oxide layer. Each groove has a width of 1 mum or less, and a width of a semiconductor material intervening between two adjacent grooves is 81.8% or more with respect to the groove width.