Abstract: A semiconductor device fabrication method applies a diazo novolac photoresist to a semiconductor wafer, followed by light exposure of its entire surface to form an underlying resist layer; forms a surface resist layer thereover; performs patterned-light exposure and heat treatment to the photoresist film consisting of the two resist layers formed; and exposes its entire surface to light, followed by development to process the photoresist film into a resist pattern, where the surface resist layer is in an inverse tapered shape, while the underlying resist layer is in an undercut shape relative to the surface resist layer.

Abstract: A semiconductor device fabrication method applies a diazo novolac photoresist to a semiconductor wafer, followed by light exposure of its entire surface to form an underlying resist layer; forms a surface resist layer thereover; performs patterned-light exposure and heat treatment to the photoresist film consisting of the two resist layers formed; and exposes its entire surface to light, followed by development to process the photoresist film into a resist pattern, where the surface resist layer is in an inverse tapered shape, while the underlying resist layer is in an undercut shape relative to the surface resist layer.

Abstract: A LED monolithic array type like emitting device which has a plurality of light emitting parts. The device is particularly suitable as a light source for printers. Each light emitting part has a light emitting diode having a laminate structure. The laminate structure has an end-type GaAs substrate and, epitaxially grown on the n-type substrate in the following order: 1) an n-type GaSa buffer layer, an n-type laminated reflection film formed of layer pairs, each having AlGaAs layers different from each other in aluminum composition ratio, an n-type AlGaAs lower cladding layer, a p-type or undoped AlGaAs active layer, a p-type AlGaAs upper cladding layer and a p-type AlGaAs contact layer. Each layer pair making up the laminated reflection film has an AlX1GA1−X1As layer and an AlX2GA1−X2As layer where X1 and X2 represent the Al composition ratio.

Abstract: A LED monolithic array type like emitting device which has a plurality of light emitting parts. The device is particularly suitable as a light source for printers. Each light emitting part has a light emitting diode having a laminate structure. The laminate structure has an end-type GaAs substrate and, epitaxially grown on the n-type substrate in the following order: 1) an n-type GaSa buffer layer, an n-type laminated reflection film formed of layer pairs, each having AlGaAs layers different from each other in aluminum composition ratio, an n-type AlGaAs lower cladding layer, a p-type or undoped AlGaAs active layer, a p-type AlGaAs upper cladding layer and a p-type AlGaAs contact layer. Each layer pair making up the laminated reflection film has an AlX1GA1−X1As layer and an AlX2GA1−X2As layer where X1 and X2 represent the Al composition ratio.

Abstract: A contact layer having a low resistance in an LED is extended from an inside edge of a light take-out region in a light emitting dot to a central position thereof, whereby an input current in the light take-out region expands, while an electrode is extended from an inside edge of the light take-out region to the center of the light take-out region so as to shape like substantially a letter T with a length which is not over the center, whereby increase in an electrode covering ratio in the light take-out region can be suppressed. As a result, a uniform light output in the light take-out region can be attained, so that a light output can be remarkably improved.