Silicon-on-Insulator biosensor devices

A semiconductor device 1 for the detection of specific biomolecular interactions is based on Silicon-on-Insulator (SOI) technology. The device comprises a substrate 2 having an SOI structure and an in-plane-gate field-effect transistor (FET) 3. The substrate 2 has, from bottom to top, a bulk silicon layer 22, a buried oxide layer 24, a single-crystal silicon layer 26. A thin, natural oxide layer 28 is formed on the silicon layer 26. The device surface is made biofunctional by binding receptors such as antibodies 46 to it. When an analyte such as a protein 52 binds itself to such a receptor it changes the device's surface potential. Any change of surface potential changes the lateral conductivity of the SOI layer 26. Such a biosensor device can allow the identification of specific interactions between biomolecules in a highly parallel and highly sensitive way.