Patent ID: 8723234

Claim:
A semiconductor device comprising: a semiconductor substrate; a plurality of field-effect transistors which are arranged to be bent back symmetrically in multi-finger structures formed on the semiconductor substrate; and a diode forming area which is adjacent to a forming area of the field-effect transistors, wherein the diode forming area is insulated from the forming area of the transistors on the semiconductor substrate, and comprises a first diode electrode in which a gate electrode of one of the field-effect transistors is placed in contact with the semiconductor substrate by means of at least one of a Schottky barrier junction contact and an ohmic contact through at least one of a bus wiring and a pad, a second diode electrode in which a source electrode of said one of the field-effect transistors is placed in contact with the semiconductor substrate by means of at least one of an ohmic contact and a Schottky barrier junction contact through at least one of a bus wiring and a pad to form a diode between the gate electrode and the source electrode and the diode forming area is formed between the forming area of the field-effect transistors and a bus wiring or a pad of the source electrode, in the first diode electrode, an electrode to be placed in Schottky barrier junction and an electrode to be placed in ohmic contact which are electrically insulated from each other on the semiconductor substrate are alternately arranged, in the second diode electrode, an electrode to be placed in ohmic contact and an electrode to be placed in Schottky barrier junction which are electrically insulated from each other on the semiconductor substrate are alternately arranged, the first diode electrode with Schottky barrier junction and the second diode electrode with ohmic contact form a first diode, the first diode electrode with ohmic contact and the second diode electrode with Schottky barrier junction form a second diode, an area of the first diode and an area of second diode are insulated on the semiconductor substrate, and a bidirectional diode is formed from the first diode and second diode whose diode-direction oppose to each other.