Abstract: A disclosed power storage device includes a power storage element, a case with a bottomed cylindrical shape having an opening at one end and housing the power storage element, and a sealing member for sealing the opening. The case has, in a vicinity of the opening, a first pressing portion pressing a side surface of the sealing member and protruding inward of the case, and a gas vent portion disposed nearer to the one end of the case than an apex which is the most protruded point of the first pressing portion. This can provide a power storage device including an explosion-proof mechanism that has high operational reliability and does not impair airtightness.

Abstract: An etching device may include a reservoir storing an etchant, a support member configured to support the semiconductor wafer in a state where a first surface of the semiconductor wafer is immersed in the etchant, a light source configured to irradiate the first surface of the semiconductor wafer supported by the support member with light emitted from the light source, an electrode disposed in the reservoir, and a power source configured to apply a current between the electrode and the semiconductor wafer supported by the support member, the current changing between a first current value and a second current value larger than the first current value.

Abstract: An etching device may include a reservoir storing an etchant, a support member configured to rotatably support the semiconductor wafer in a state where a first surface of the semiconductor wafer is immersed in the etchant, a light source configured to emit light to the first surface of the semiconductor wafer, a counter electrode disposed in the reservoir and disposed between the support member and the light source, and a power source configured to apply a voltage between the semiconductor wafer and the counter electrode. When the light source emits light, a lighted area by the light and a shadow of the counter electrode may be projected onto the first surface of the semiconductor wafer, and when the semiconductor wafer is rotated by the support member, at least a part of the first surface may pass both the lighted area and the shadow.

Abstract: An etching apparatus having a liquid bath storing an etching liquid, a substrate installation part capable of supporting the semiconductor substrate in vertical placement at a position at which a treatment surface of the semiconductor substrate is immersed in the etching liquid, a sample electrode provided at the substrate installation part and electrically connected to the semiconductor substrate, a counter electrode disposed at a position at which the counter electrode is immersed in the etching liquid in the liquid bath, a light source irradiating the treatment surface of the semiconductor substrate with light, and an irradiation window provided between the treatment surface of the semiconductor substrate and the light source and at a position separated from the semiconductor substrate in a horizontal direction.

Abstract: An etching apparatus having a liquid bath storing an etching liquid, a substrate installation part capable of supporting the semiconductor substrate in vertical placement at a position at which a treatment surface of the semiconductor substrate is immersed in the etching liquid, a sample electrode provided at the substrate installation part and electrically connected to the semiconductor substrate, a counter electrode disposed at a position at which the counter electrode is immersed in the etching liquid in the liquid bath, a light source irradiating the treatment surface of the semiconductor substrate with light, and an irradiation window provided between the treatment surface of the semiconductor substrate and the light source and at a position separated from the semiconductor substrate in a horizontal direction.

Abstract: Provided are a vertical nitride semiconductor device in which occurrence of leak currents can be suppressed, and a method for manufacturing such nitride semiconductor device. A nitride semiconductor device, which is a vertical HEMT, is provided with an n? type GaN first nitride semiconductor layer, p+ type GaN second nitride semiconductor layers, an n? type GaN third nitride semiconductor layer, and an n? type AlGaN fourth nitride semiconductor layer that is in hetero junction with a front surface of the third nitride semiconductor layer. Openings that penetrate the third nitride semiconductor layer and reach front surfaces of the second nitride semiconductor layers are provided at positions isolated from the peripheral edge of the third nitride semiconductor layer. Source electrodes are provided in the openings. Etching damage that is in contact with the source electrodes is surrounded by a region where no etching damage is formed.