Patent ID: 8148213

Claim:
A method for manufacturing a biosensor including: a silicon substrate; a first silicon oxide film formed on one surface of the silicon substrate; a reaction field formed on the first silicon oxide film; a gate electrode formed on or above the first silicon oxide film; a second silicon oxide film formed on the other surface of the silicon substrate; a source electrode formed on the second silicon oxide film; a drain electrode formed on the second silicon oxide film; and a channel connecting the source electrode and the drain electrode, the channel formed on the second silicon oxide film, the method comprising: forming a laminate of a first silicon oxide film and a polysilicon film on one surface of a silicon substrate; forming a second silicon oxide film on the other surface of the silicon substrate; forming a source electrode, a drain electrode, and a channel on the second silicon oxide film, the channel connecting the source electrode and the drain electrode; removing the polysilicon film; and disposing a gate electrode on or above the one surface of the silicon substrate.