Semiconductor die having a variable thickness device layer

Abstract

A semiconductor die includes: a silicon-on-insulator (SOI) substrate having a silicon device layer, a bulk silicon substrate, and a buried oxide layer separating the silicon device layer from the bulk silicon substrate; a lateral power MOSFET (metal-oxide-semiconductor field-effect transistor) in a first device region of the silicon device layer; and an additional semiconductor device in a second device region of the silicon device layer and having a lower breakdown voltage than the lateral power MOSFET. The silicon device layer has a first thickness in a first part of the first device region and a second thickness in a second part of the first device region, the second thickness being greater than the first thickness. The silicon device layer has the first thickness throughout the second device region. Additional semiconductor die embodiments are also described.

Dependencies are inferred from the claim text.