Abstract: A vertical semiconductor device in which pinch-off characteristics and breakdown voltage characteristics can be stably improved by fixing the electric potential of a p-type GaN barrier layer with certainty is provided. The semiconductor device includes a GaN-based stacked layer having an opening, a regrown layer including a channel located so as to cover a wall surface of the opening, an n+-type source layer that is in ohmic contact with the source electrode, a p-type GaN barrier layer, and a p+-type GaN-based supplementary layer located between the p-type GaN barrier layer and the n+-type source layer. The p+-type GaN-based supplementary layer and the n+-type source layer form a tunnel junction to fix the electric potential of the p-type GaN barrier layer at a source potential.

Abstract: It is an object to improve the breakdown voltage characteristics of a vertical semiconductor device having an opening and including a channel formed of two-dimensional electron gas in the opening. A GaN-based stacked layer 15 includes n?-type GaN drift layer 4/p-type GaN barrier layer 6/n+-type GaN contact layer 7. An opening 28 extends from a top layer and reaches the n?-type GaN drift layer 4. The semiconductor device includes a regrown layer 27 located so as to cover a wall surface and a bottom portion of the opening, the regrown layer 27 including an electron drift layer 22 and an electron source layer 26, a source electrode S located around the opening, a gate electrode G located on the regrown layer in the opening, and a bottom insulating layer 37 located in the bottom portion of the opening.

Abstract: It is an object to improve the breakdown voltage characteristics of a vertical semiconductor device having an opening and including a channel formed of two-dimensional electron gas in the opening. The vertical semiconductor device includes a GaN-based stacked layer 15 having an opening 28 and the GaN-based stacked layer 15 includes n-type GaN-based drift layer 4/p-type GaN-based barrier layer 6/n-type GaN-based contact layer 7. The vertical semiconductor device includes a regrown layer 27 located so as to cover the opening, the regrown layer 27 including an electron drift layer 22 and an electron supply layer 26, a source electrode S, and a gate electrode G located on the regrown layer. The gate electrode G covers a portion having a length corresponding to the thickness of the p-type GaN-based barrier layer and is terminated at a position on the wall surface, the position being away from the bottom portion of the opening.

Abstract: In a vertical semiconductor device including a channel in an opening, a semiconductor device whose high-frequency characteristics can be improved and a method for producing the semiconductor device are provided. The semiconductor device includes n-type GaN-based drift layer 4/p-type GaN-based barrier layer 6/n-type GaN-based contact layer 7. An opening 28 extends from a top layer and reaches the n-type GaN-based drift layer. The semiconductor device includes a regrown layer 27 located so as to cover the opening, the regrown layer 27 including an electron drift layer 22 and an electron supply layer 26, a source electrode S, a drain electrode D, and a gate electrode G located on the regrown layer. Assuming that the source electrode serving as one electrode and the drain electrode serving as the other electrode constitute a capacitor, the semiconductor device includes a capacitance-decreasing structure that decreases the capacitance of the capacitor.

Abstract: There is provided a vertical GaN-based semiconductor device in which the on-resistance can be decreased while the breakdown voltage characteristics are improved using a p-type GaN barrier layer. The semiconductor device includes a regrown layer 27 including a channel located on a wall surface of an opening 28, a p-type barrier layer 6 whose end face is covered, a source layer 7 that is in contact with the p-type barrier layer, a gate electrode G located on the regrown layer, and a source electrode S located around the opening. In the semiconductor device, the source layer has a superlattice structure that is constituted by a stacked layer including a first layer (a layer) having a lattice constant smaller than that of the p-type barrier layer and a second layer (b layer) having a lattice constant larger than that of the first layer.

Abstract: A method for fabricating a semiconductor device includes: forming a GaN-based semiconductor layer on a substrate; forming a gate insulating film of aluminum oxide on the GaN-based semiconductor layer at a temperature equal to or lower than 450° C.; forming a protection film on an upper surface of the gate insulating film; performing a process with an alkaline solution in a state in which the upper surface of the gate insulating film is covered with the protection film; and forming a gate electrode on the gate insulating film.

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: In a vertical semiconductor device including a channel in an opening, a semiconductor device whose high-frequency characteristics can be improved and a method for producing the semiconductor device are provided. The semiconductor device includes n-type GaN-based drift layer 4/p-type GaN-based barrier layer 6/n-type GaN-based contact layer 7. An opening 28 extends from a top layer and reaches the n-type GaN-based drift layer. The semiconductor device includes a regrown layer 27 located so as to cover the opening, the regrown layer 27 including an electron drift layer 22 and an electron supply layer 26, a source electrode S, a drain electrode D, and a gate electrode G located on the regrown layer. Assuming that the source electrode serving as one electrode and the drain electrode serving as the other electrode constitute a capacitor, the semiconductor device includes a capacitance-decreasing structure that decreases the capacitance of the capacitor.

Abstract: There is provided a semiconductor device or the like which includes a channel and a gate electrode in an opening and in which electric field concentration near a bottom portion of the opening can be reduced. The semiconductor device includes n?-type GaN drift layer 4/p-type GaN barrier layer 6/n+-type GaN contact layer. An opening 28 extends from the top layer and reaches the n-type GaN-based drift layer. The semiconductor device includes a regrown layer 27 located in the opening, the regrown layer 27 including an electron supply layer 26 and an electron drift layer 22, a source electrode S, a drain electrode D, a gate electrode G located on the regrown layer, and a semiconductor impurity adjustment region 31 disposed in the bottom portion of the opening. The impurity adjustment region 31 is a region that promotes a potential drop from the drain electrode side to the gate electrode side in a potential distribution in an off-state.

Abstract: It is an object to improve the breakdown voltage characteristics of a vertical semiconductor device having an opening and including a channel formed of two-dimensional electron gas in the opening. A GaN-based stacked layer 15 includes n?-type GaN drift layer 4/p-type GaN barrier layer 6/n+-type GaN contact layer 7. An opening 28 extends from a top layer and reaches the n?-type GaN drift layer 4. The semiconductor device includes a regrown layer 27 located so as to cover a wall surface and a bottom portion of the opening, the regrown layer 27 including an electron drift layer 22 and an electron source layer 26, a source electrode S located around the opening, a gate electrode G located on the regrown layer in the opening, and a bottom insulating layer 37 located in the bottom portion of the opening.

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.

Abstract: It is an object to improve the breakdown voltage characteristics of a vertical semiconductor device having an opening and including a channel formed of two-dimensional electron gas in the opening. The vertical semiconductor device includes a GaN-based stacked layer 15 having an opening 28 and the GaN-based stacked layer 15 includes n-type GaN-based drift layer 4/p-type GaN-based barrier layer 6/n-type GaN-based contact layer 7. The vertical semiconductor device includes a regrown layer 27 located so as to cover the opening, the regrown layer 27 including an electron drift layer 22 and an electron supply layer 26, a source electrode S, and a gate electrode G located on the regrown layer. The gate electrode G covers a portion having a length corresponding to the thickness of the p-type GaN-based barrier layer and is terminated at a position on the wall surface, the position being away from the bottom portion of the opening.

Abstract: There is provided a vertical GaN-based semiconductor device in which the on-resistance can be decreased while the breakdown voltage characteristics are improved using a p-type GaN barrier layer. The semiconductor device includes a regrown layer 27 including a channel located on a wall surface of an opening 28, a p-type barrier layer 6 whose end face is covered, a source layer 7 that is in contact with the p-type barrier layer, a gate electrode G located on the regrown layer, and a source electrode S located around the opening. In the semiconductor device, the source layer has a superlattice structure that is constituted by a stacked layer including a first layer (a layer) having a lattice constant smaller than that of the p-type barrier layer and a second layer (b layer) having a lattice constant larger than that of the first layer.

Abstract: A vertical semiconductor device in which pinch-off characteristics and breakdown voltage characteristics can be stably improved by fixing the electric potential of a p-type GaN barrier layer with certainty is provided. The semiconductor device includes a GaN-based stacked layer having an opening, a regrown layer including a channel located so as to cover a wall surface of the opening, an n+-type source layer that is in ohmic contact with the source electrode, a p-type GaN barrier layer, and a p+-type GaN-based supplementary layer located between the p-type GaN barrier layer and the n+-type source layer. The p+-type GaN-based supplementary layer and the n+-type source layer form a tunnel junction to fix the electric potential of the p-type GaN barrier layer at a source potential.

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.

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 semiconductor device includes a substrate, a GaN-based semiconductor layer formed on the substrate, a gate electrode embedded in the GaN-based semiconductor layer, a source electrode and a drain electrode formed on both sides of the gate electrode, a first recess portion formed between the gate electrode and the source electrode, and a second recess portion formed between the gate electrode and the drain electrode. The first recess portion has a depth deeper than that of the second recess portion.

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 semiconductor device includes a GaN-based semiconductor layer formed on a substrate, a gate insulating film that is formed on a surface of the GaN-based semiconductor layer and is made of aluminum oxide, and a gate electrode formed on the gate insulating film, the gate insulating film having a carbon concentration of 2×1020/cm3 or less.

Abstract: A method for fabricating a semiconductor device includes: forming a GaN-based semiconductor layer on a substrate; forming a gate insulating film of aluminum oxide on the GaN-based semiconductor layer at a temperature equal to or lower than 450° C.; forming a protection film on an upper surface of the gate insulating film; performing a process with an alkaline solution in a state in which the upper surface of the gate insulating film is covered with the protection film; and forming a gate electrode on the gate insulating film.