Abstract: Provided is a GaAs wafer having suppressed carrier concentration and low dislocation density, as well as a large proportion of the area of a region with zero dislocation density to the GaAs wafer surface. The GaAs wafer has a silicon concentration of 1.0×1017 cm?3 or more and less than 1.1×1018 cm?3; an indium concentration of 3.0×1018 cm?3 or more and less than 3.0×1019 cm?3; a boron concentration of 2.5×1018 cm?3 or more; a carrier concentration of 1.0×1016 cm?3 or more and 4.0×1017 cm?3 or less; and a proportion of the area of a region with zero dislocation density to the wafer surface of 91.0% or more.

Abstract: Provided is a GaAs wafer that can suitably be used to produce LiDAR sensors in particular and a method of producing a GaAs ingot that can be used to obtain such a GaAs wafer. The GaAs wafer has a silicon concentration of 5.0×1017 cm?3 or more and less than 3.5×1018 cm?3, an indium concentration of 3.0×1017 cm?3 or more and less than 3.0×1019 cm?3, and a boron concentration of 1.0×1018 cm?3 or more. The average dislocation density of the GaAs wafer is 1500/cm2 or less.

Abstract: Provided is a GaAs ingot with which a GaAs wafer having a carrier concentration of 5.5×1017 cm?3 or less and low dislocation density with an average dislocation density of 500/cm2 or less can be obtained by adding a small amount of In with Si. A seed side end and a center portion of a straight body part of the GaAs ingot each have a silicon concentration of 2.0×1017 cm?3 or more and less than 1.5×1018 cm?3, an indium concentration of 1.0×1017cm?3 or more and less than 6.5×1018 cm?3, a carrier concentration of 5.5×1017 cm?3 or less, and an average dislocation density of 500/cm2 or less.

Abstract: An electronic part mounting substrate includes: a metal plate 10 (for mounting thereon electronic parts) of aluminum or an aluminum alloy having a substantially rectangular planar shape, one major surface of the metal plate 10 being surface-processed so as to have a surface roughness of not less than 0.2 micrometers; a plating film 20 of nickel or a nickel alloy formed on the one major surface of the metal plate 10; an electronic part 14 bonded to the plating film 20 by a silver bonding layer 12 (containing a sintered body of silver); a ceramic substrate having a substantially rectangular planar shape, one major surface of the ceramic substrate 16 being bonded to the other major surface of the metal plate 10; and a radiating metal plate (metal base plate) 18 bonded to the other major surface of the ceramic substrate 16.

Abstract: An electronic part mounting substrate includes: a metal plate 10 (for mounting thereon electronic parts) of aluminum or an aluminum alloy having a substantially rectangular planar shape, one major surface of the metal plate 10 being surface-processed so as to have a surface roughness of not less than 0.2 micrometers; a plating film 20 of nickel or a nickel alloy formed on the one major surface of the metal plate 10; an electronic part 14 bonded to the plating film 20 by a silver bonding layer 12 (containing a sintered body of silver); a ceramic substrate 16 having a substantially rectangular planar shape, one major surface of the ceramic substrate 16 being bonded to the other major surface of the metal plate 10; and a radiating metal plate (metal base plate) 18 bonded to the other major surface of the ceramic substrate 16.

Abstract: In a method for producing an electronic part mounting substrate wherein an electronic part 14 is mounted on one major surface (a surface to which the electronic part 14 is to be bonded) of the metal plate 10 of copper, or aluminum or the aluminum alloy (when a plating film 20 of copper is formed on the surface), the one major surface of the metal plate 10 (or the surface of the plating film 20 of copper) is surface-machined to be coarsened so as to have a surface roughness of not less than 0.4 ?m, and then, a silver paste is applied on the surface-machined major surface (or the surface-machined surface of the plating film 20 of copper) to arrange the electronic part 14 thereon to sinter silver in the silver paste to form a silver bonding layer 12 to bond the electronic part 14 to the one major surface of the metal plate 10 (or the surface of the plating film 20 of copper) with the silver bonding layer 12.

Abstract: In a method for producing an electronic part mounting substrate wherein an electronic part 14 is mounted on one major surface (a surface to which the electronic part 14 is to be bonded) of the metal plate 10 of copper, or aluminum or the aluminum alloy (when a plating film 20 of copper is formed on the surface), the one major surface of the metal plate 10 (or the surface of the plating film 20 of copper) is surface-machined to be coarsened so as to have a surface roughness of not less than 0.4 ?m, and then, a silver paste is applied on the surface-machined major surface (or the surface-machined surface of the plating film 20 of copper) to arrange the electronic part 14 thereon to sinter silver in the silver paste to form a silver bonding layer 12 to bond the electronic part 14 to the one major surface of the metal plate 10 (or the surface of the plating film 20 of copper) with the silver bonding layer 12.

Abstract: An electronic part mounting substrate includes: a metal plate 10 (for mounting thereon electronic parts) of aluminum or an aluminum alloy having a substantially rectangular planar shape, one major surface of the metal plate 10 being surface-processed so as to have a surface roughness of not less than 0.2 micrometers; a plating film 20 of nickel or a nickel alloy formed on the one major surface of the metal plate 10; an electronic part 14 bonded to the plating film 20 by a silver bonding layer 12 (containing a sintered body of silver); a ceramic substrate having a substantially rectangular planar shape, one major surface of the ceramic substrate 16 being bonded to the other major surface of the metal plate 10; and a radiating metal plate (metal base plate) 18 bonded to the other major surface of the ceramic substrate 16.

Abstract: There is provided a notched compound semiconductor crystal having the same specification even if it is turned over. With respect to a compound semiconductor wafer produced by slicing a compound semiconductor crystal having a crystal plane of (100) plane, the crystal is sliced so as to be tilted from the (100) plane in a direction of [101] or [10-1] when a notch is formed in a direction of [010], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [0-10] or [010] when a notch is formed in a direction of [001], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [001] or [00-1] when a notch is formed in a direction of [0-10] , or the crystal is sliced so as to be tilted from the (100) plane in a direction of [010] or [0-10] when a notch is formed in a direction of [00-1].

Abstract: There is provided a notched compound semiconductor crystal having the same specification even if it is turned over. With respect to a compound semiconductor wafer produced by slicing a compound semiconductor crystal having a crystal plane of (100) plane, the crystal is sliced so as to be tilted from the (100) plane in a direction of [101] or [10-1] when a notch is formed in a direction of [010], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [0-10] or [010] when a notch is formed in a direction of [001], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [001] or [00-1] when a notch is formed in a direction of [0-10], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [010] or [0-10] when a notch is formed in a direction of [00-1].

Abstract: There is provided a notched compound semiconductor crystal having the same specification even if it is turned over. With respect to a compound semiconductor wafer produced by slicing a compound semiconductor crystal having a crystal plane of (100) plane, the crystal is sliced so as to be tilted from the (100) plane in a direction of [101] or [10-1] when a notch is formed in a direction of [010], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [0-10] or [010] when a notch is formed in a direction of [001], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [001] or [00-1] when a notch is formed in a direction of [0-10], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [010] or [0-10] when a notch is formed in a direction of [00-1].

Abstract: An improvement in electrode reliability is realized by preventing over-etching on a peripheral lower portion of an electrode while maintaining the flow of steps of roughening a surface after forming the electrode on a semiconductor substrate. After a P-side electrode 4 is formed on a main surface 3a of a semiconductor substrate 3, a surface of the P-side electrode 4 is selectively covered with a protective film 12, after the semiconductor substrate 3 is cut into chips, the surface is roughened from above the protective film 12, the main surface 3a around the P-side electrode 4 and a side surface are roughened with a non-chemical treatment region 10 which is a non-roughened surface region being left in a peripheral portion of the P-side electrode 4 covered with the protective film 12, and thereafter the protective film 12 is removed.

Abstract: There is provided a notched compound semiconductor crystal having the same specification even if it is turned over. With respect to a compound semiconductor wafer produced by slicing a compound semiconductor crystal having a crystal plane of (100) plane, the crystal is sliced so as to be tilted from the (100) plane in a direction of [101] or [10-1] when a notch is formed in a direction of [010], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [0-10] or [010] when a notch is formed in a direction of [001], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [001] or [00-1] when a notch is formed in a direction of [0-10], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [010] or [0-10] when a notch is formed in a direction of [00-1].

Abstract: There is provided a notched compound semiconductor crystal having the same specification even if it is turned over. With respect to a compound semiconductor wafer produced by slicing a compound semiconductor crystal having a crystal plane of (100) plane, the crystal is sliced so as to be tilted from the (100) plane in a direction of [101] or [10-1] when a notch is formed in a direction of [010], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [0-10] or [010] when a notch is formed in a direction of [001], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [001] or [00-1] when a notch is formed in a direction of [0-10], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [010] or [0-10] when a notch is formed in a direction of [00-1].

Abstract: There is provided a notched compound semiconductor crystal having the same specification even if it is turned over. With respect to a compound semiconductor wafer produced by slicing a compound semiconductor crystal having a crystal plane of (100) plane, the crystal is sliced so as to be tilted from the (100) plane in a direction of [101] or [10-1] when a notch is formed in a direction of [010], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [0-10] or [010] when a notch is formed in a direction of [001], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [001] or [00-1] when a notch is formed in a direction of [0-10] , or the crystal is sliced so as to be tilted from the (100) plane in a direction of [010] or [0-10] when a notch is formed in a direction of [00-1].

Abstract: There is provided a notched compound semiconductor crystal having the same specification even if it is turned over. With respect to a compound semiconductor wafer produced by slicing a compound semiconductor crystal having a crystal plane of (100) plane, the crystal is sliced so as to be tilted from the (100) plane in a direction of [101] or [10?1] when a notch is formed in a direction of [010], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [0?10] or [010] when a notch is formed in a direction of [001], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [001] or [00?1] when a notch is formed in a direction of [0?10], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [010] or [0?10] when a notch is formed in a direction of [00?1].

Abstract: An improvement in electrode reliability is realized by preventing over-etching on a peripheral lower portion of an electrode while maintaining the flow of steps of roughening a surface after forming the electrode on a semiconductor substrate. After a P-side electrode 4 is formed on a main surface 3a of a semiconductor substrate 3, a surface of the P-side electrode 4 is selectively covered with a protective film 12, after the semiconductor substrate 3 is cut into chips, the surface is roughened from above the protective film 12, the main surface 3a around the P-side electrode 4 and a side surface are roughened with a non-chemical treatment region 10 which is a non-roughened surface region being left in a peripheral portion of the P-side electrode 4 covered with the protective film 12, and thereafter the protective film 12 is removed.

Abstract: There is provided a notched compound semiconductor crystal having the same specification even if it is turned over. With respect to a compound semiconductor wafer produced by slicing a compound semiconductor crystal having a crystal plane of (100) plane, the crystal is sliced so as to be tilted from the (100) plane in a direction of [101] or [10-1] when a notch is formed in a direction of [010], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [0-10] or [010] when a notch is formed in a direction of [001], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [001] or [00-1] when a notch is formed in a direction of [0-10], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [010] or [0-10] when a notch is formed in a direction of [00-1].