Abstract: A semiconductor device includes a laminated layer structure including at least one semiconductor layer disposed on a first conductivity type semiconductor substrate, a semi-insulating semiconductor layer disposed on the semiconductor laminated layer structure, a second conductivity type semiconductor region disposed on the front surface of the semi-insulating semiconductor layer, a first electrode on the rear surface of the substrate, and a second electrode disposed on the semi-insulating semiconductor layer and in ohmic contact with the second conductivity type semiconductor region.

Abstract: In a photodiode, p-type background light capture regions at least partially surround a p-type light sensing region and are spaced at a distance from the light sensing region. Holes generated in response to background light are captured by depletion layers of the background light capture regions and do not influence photocurrent. Thus, no deterioration in response speed occurs and the response speed is increased.

Abstract: A method of fabricating a semiconductor wafer includes preparing a semiconductor wafer of a monocrystalline compound semiconductor having a side surface and upper and lower surfaces, and upper and lower corners at the intersections of the side surface and the upper and lower surfaces, respectively; and producing a non-monocrystalline region at the side surface of the semiconductor wafer including the corners. Since the semiconductor wafer includes a non-monocrystalline part at the side surface including the corners, even when a crack is produced in the non-monocrystalline part, unwanted cleaving of the wafer from the crack does not occur.

Abstract: An impurity is diffused into semiconductor epitaxial layers of a semiconductor device from a solid phase diffusion source through an additional thin film layer disposed on the epitaxial layers of the structure. After the diffusion, the thin film layer is removed. The material of the additional thin film layer has physical properties approximating those of the epitaxial layers. Accordingly, no crystallographic defects such as dislocations are introduced into the epitaxial layers by heat treatment, and, accordingly, the resulting device has reduced leakage current.

Abstract: A method of making an avalanche photodiode includes depositing a light-absorbing semiconductor layer of a first conductivity type on a semiconductor substrate of the first conductivity type; successively depositing multiple pairs of semiconductor layers on the light-absorbing layer, each of the pairs including a first semiconductor layer of the first conductivity type containing a first dopant impurity concentration and a second semiconductor layer of the first conductivity type containing a second dopant impurity concentration smaller than the first dopant impurity concentration; and forming a semiconductor light-receiving layer of a second conductivity type on the pairs of layers to form a pn junction with the pairs of layers.

Abstract: A novel avalanche photodiode includes an n-type semiconductor substrate, an n-type light-absorbing layer on the substrate, an n-type multiplication layer on the light-absorbing layer, and a p-type light-receiving layer. The multiplication layer includes a plurality of pairs of semiconductor layers, with each pair including one high dopant impurity concentration layer and one low dopant impurity concentration layer.

Abstract: A fast-response semiconductor photodetector device includes a semiconductor light-absorptive layer of a first conductivity type disposed on a semiconductor substrate of the first conductivity type, and a light-transmissive layer on the light-absorptive layer having a smaller relative dielectric constant than the light-absorptive layer. A semiconductor region of a second conductivity type is selectively formed in the light-transmissive layer to a depth which is less than the thickness of the light-transmissive layer. The second conductivity type region has includes extensions extending into the light-absorptive layer.