摘要 |
In a semiconductor device, a logic MOSFET and a switch MOSFET are formed in a high-resistance substrate. The logic MOSFET includes an epitaxial layer formed on the high-resistance substrate and a well layer formed on the epitaxial layer. The switch MOSFET includes a LOCOS oxide film formed on the high-resistance substrate, the LOCOS oxide film being sandwiched between trenches and thus having a mesa-shape in its upper part. The switch MOSFET further includes a buried oxide film and a SOI layer formed on the mesa-shape of the LOCOS oxide film. The upper surface of the mesa-shape of the LOCOS oxide film is positioned at the same height as the upper surface of the epitaxial layer. |