Abstract: A display device includes a display panel that includes a first hole and a device housing that is configured such that the display panel is fastened and fixed to the device housing by a screw passed through the first hole and screwed into the screw hole. The display panel includes a display-side positioning part which is configured to fit to a portion of the device housing to perform positioning of the display panel with respect to the device housing and which includes the first hole, and the device housing includes a housing-side positioning part which is configured to fit to the display-side positioning part to perform the positioning and which includes a second hole formed so as to communicate with the first hole when the housing-side positioning part is fitted to the display-side positioning part.

Abstract: method of manufacturing a semiconductor device capable of manufacturing a miniaturized semiconductor device is provided. The method of manufacturing a semiconductor device according to an embodiment includes the steps of: preparing a semiconductor substrate having a first surface and a second surface which is an opposite surface of the first surface; forming a hard mask having an opening on the first surface; forming a gate trench extending toward the second surface on the first surface using the hard mask as a mask; widening the width of the opening; filling the opening with an interlayer insulating film; and forming a contact hole in the interlayer insulating film by removing the hard mask.

Abstract: method of manufacturing a semiconductor device capable of manufacturing a miniaturized semiconductor device is provided. The method of manufacturing a semiconductor device according to an embodiment includes the steps of: preparing a semiconductor substrate having a first surface and a second surface which is an opposite surface of the first surface; forming a hard mask having an opening on the first surface; forming a gate trench extending toward the second surface on the first surface using the hard mask as a mask; widening the width of the opening; filling the opening with an interlayer insulating film; and forming a contact hole in the interlayer insulating film by removing the hard mask.

Abstract: An electrode comes in ohmic contact with an AlGaN layer. A semiconductor device SD has a nitride semiconductor layer GN2, and an AlxGa(1-x)N layer AGN (hereinafter referred to as “AlGaN layer AGN), and Al electrodes DE, SE. in the AlGaN layer AGN, 0<x?0.2 is satisfied. Also, both of a concentration of a p-type impurity and a concentration of an n-type impurity in the AlGaN layer AGN are 1×1016 cm?3 or lower. In this example, the p-type impurity is exemplified by, for example, Be, C, and Mg, and the n-type impurity is exemplified by Si, S, and Se. Also, the Al electrodes DE and SE are connected to the AlGaN layer AGN. Because a composition ratio of Al is limited to the above-mentioned range, the Al electrodes DE and SE are brought into ohmic contact with the AlGaN layer AGN.

Abstract: To improve performance of a semiconductor device. For example, on the assumption that a superlattice layer is inserted between a buffer layer and a channel layer, a concentration of acceptors introduced into nitride semiconductor layers forming a part of the superlattice layer is higher than a concentration of acceptors introduced into nitride semiconductor layers forming the other part of the superlattice layer. That is, the concentration of acceptors introduced into the nitride semiconductor layers having a small band gap is higher than the concentration of acceptors introduced into the nitride semiconductor layers having a large band gap.

Abstract: The reliability of a field effect transistor made of a nitride semiconductor material is improved. An ohmic electrode includes a plurality of unit electrodes isolated to be separated from each other. With this configuration, an on-state current can be prevented from flowing in the unit electrodes in a y-axial direction (negative direction). Further, in the respective unit electrodes, a current density of the on-state current flowing in the y-axial direction (negative direction) can be prevented from increasing. As a result, an electromigration resistance of the ohmic electrode can be improved.

Abstract: The reliability of a field effect transistor made of a nitride semiconductor material is improved. An ohmic electrode includes a plurality of unit electrodes isolated to be separated from each other. With this configuration, an on-state current can be prevented from flowing in the unit electrodes in a y-axial direction (negative direction). Further, in the respective unit electrodes, a current density of the on-state current flowing in the y-axial direction (negative direction) can be prevented from increasing. As a result, an electromigration resistance of the ohmic electrode can be improved.

Abstract: An electrode comes in ohmic contact with an AlGaN layer. A semiconductor device SD has a nitride semiconductor layer GN2, and an AlxGa(1?x)N layer AGN (hereinafter referred to as “AlGaN layer AGN), and Al electrodes DE, SE. in the AlGaN layer AGN, 0<X?0.2 is satisfied. Also, both of a concentration of a p-type impurity and a concentration of an n-type impurity in the AlGaN layer AGN are 1×1016 cm?3 or lower. In this example, the p-type impurity is exemplified by, for example, Be, C, and Mg, and the n-type impurity is exemplified by Si, S, and Se. Also, the Al electrodes DE and SE are connected to the AlGaN layer AGN. Because a composition ratio of Al is limited to the above-mentioned range, the Al electrodes DE and SE are brought into ohmic contact with the AlGaN layer AGN.

Abstract: To improve performance of a semiconductor device. For example, on the assumption that a superlattice layer is inserted between a buffer layer and a channel layer, a concentration of acceptors introduced into nitride semiconductor layers forming a part of the superlattice layer is higher than a concentration of acceptors introduced into nitride semiconductor layers forming the other part of the superlattice layer. That is, the concentration of acceptors introduced into the nitride semiconductor layers having a small band gap is higher than the concentration of acceptors introduced into the nitride semiconductor layers having a large band gap.

Abstract: The reliability of a field effect transistor made of a nitride semiconductor material is improved. An ohmic electrode includes a plurality of unit electrodes isolated to be separated from each other. With this configuration, an on-state current can be prevented from flowing in the unit electrodes in a y-axial direction (negative direction). Further, in the respective unit electrodes, a current density of the on-state current flowing in the y-axial direction (negative direction) can be prevented from increasing. As a result, an electromigration resistance of the ohmic electrode can be improved.

Abstract: A method of manufacturing according to the present invention includes forming a trench to a semiconductor substrate, depositing an insulating film to the trench, etching the insulating film of a bottom part of the trench by plasma etching and thereby forming to an opening part of the trench, an inclined surface at an angle of inclination a to a principal surface of the semiconductor substrate, forming a gate insulating film from a top surface of the semiconductor substrate to the insulating film of the bottom part of the trench, and forming a gate electrode on the gate insulating film.