Substrate used as a SOI substrate comprises a layer of monocrystalline silicon, a silicon dioxide layer and a silicon substrate

摘要

Substrate comprises a layer (S) of monocrystalline silicon, a silicon dioxide layer (O) and a silicon substrate (1). Substrate comprises a layer (S) of monocrystalline silicon, a silicon dioxide layer (O) and a silicon substrate (1). A recess (V) is provided to separate the silicon and silicon dioxide layers. An upper part of the recess arranged in the region of the silicon layer is cylindrical with a horizontal first cross-section. A lower part of the recess is arranged in the region of the silicon dioxide layer and has a bulge so that it is cylindrical with a horizontal second cross-section that is larger than the first cross-section. A cylinder made of insulating material whose horizontal cross-section corresponds to the first cross-section has its lower part arranged in the lower part of the recess. The bulge is formed in such a way as to laterally surround the lower part of the cylinder. A conducting structure (L) is arranged in the bulge that borders the silicon layer and the silicon dioxide layer. Preferred Features: A MOS transistor is arranged in the silicon layer. The conducting structure electrically connects the channel region of the MOS transistor to the silicon substrate.