Patent ID: 7018904

Claim:
A method for fabricating a semiconductor chip comprising: preparing an SOI substrate consisting of a base substrate, a buried insulator on the base substrate, and a silicon layer on the insulator; selectively removing the silicon layer and the buried insulator in a predetermined area of the SOI substrate so as to form a groove at an upper portion of the buried insulator; forming a sidewall protection film covering a side face of the silicon layer revealed by the removal and a side face of the groove; exposing a portion of the base substrate by selectively removing the buried insulator from the bottom of the groove; forming a bulk growth layer from the exposed surface of the base substrate until the top face of the bulk growth layer is in alignment with the top face of the silicon layer; forming isolations having the same depth in the bulk growth layer and in the SOI substrate in a same process; and fabricating devices in the bulk growth layer and the silicon layer on the buried insulator.