Abstract: There are provided a semiconductor device that includes a bypass protection unit against surge voltage or the like, achieves good withstand voltage characteristics and low on-resistance (low On-state voltage), has a simple structure, and is used for large-current purpose and a method for producing the semiconductor device. In the present invention, the semiconductor device includes an n+-type GaN substrate 1 having a GaN layer that is in ohmic contact with a supporting substrate, a FET having an n?-type GaN drift layer 2 in a first region R1, and an SBD having an anode electrode in a second region R2, the anode electrode being in Schottky contact with the n?-type GaN drift layer 2. The FET and the SBD are arranged in parallel. A drain electrode D of the FET and a cathode electrode C of the SBD are formed on the back of the n+-type GaN substrate 1.

Abstract: A method for manufacturing a Schottky barrier diode includes the following steps. First, a GaN substrate is prepared. A GaN layer is formed on the GaN substrate. A Schottky electrode including a first layer made of Ni or Ni alloy and in contact with the GaN layer is formed. The step of forming the Schottky electrode includes a step of forming a metal layer to serve as the Schottky electrode and a step of heat treating the metal layer. A region of the GaN layer in contact with the Schottky electrode has a dislocation density of 1×108 cm?2 or less.

Abstract: There are provided a semiconductor device that includes a bypass protection unit against surge voltage or the like, achieves good withstand voltage characteristics and low on-resistance (low On-state voltage), has a simple structure, and is used for large-current purpose and a method for producing the semiconductor device. In the present invention, the semiconductor device includes an n+-type GaN substrate 1 having a GaN layer that is in ohmic contact with a supporting substrate, a FET having an n?-type GaN drift layer 2 in a first region R1, and an SBD having an anode electrode in a second region R2, the anode electrode being in Schottky contact with the d?-type GaN drift layer 2. The FET and the SBD are arranged in parallel. A drain electrode D of the FET and a cathode electrode C of the SBD are formed on the back of the n+-type GaN substrate 1.