SEMICONDUCTOR APPARATUS AND MANUFACTURING METHOD THEREOF

PROBLEM TO BE SOLVED: To suppress occurrence of crystal defects or dislocation by reducing the stress concentrating on a silicon substrate near the upper end of an STI. SOLUTION: When etching to form a side wall spacer 19 consisting of a silicon oxide film on the side wall of a gate electrode 16, over-etching is applied more than normal to etch an SOI substrate 1, so that a forward taper (t2) of at least preferably 40 nm, 70 nm or more is formed on the SOI substrate 1 at the upper end of an element separation groove 10. Since the silicon oxide film 9 embedded in the element separation groove 10 is etched at a selection ratio which is higher than the SOI substrate 1 at that time, its surface goes below the lower end of the taper (t2). COPYRIGHT: (C)2006,JPO&NCIPI