Abstract: A method for producing a compound semiconductor wafer used for production of HBT by vapor growth of a sub-collector layer, a collector layer, a base layer and an emitter layer in this turn on a compound semiconductor substrate using MOCVD method wherein the base layer is grown as a p-type compound semiconductor thin film layer containing at least one of Ga, Al and In as a Group III element and As as a Group V element under such growth conditions that the growth rate gives a growth determined by a Group V gas flow rate-feed.

Abstract: A method for producing a compound semiconductor wafer used for production of HBT by vapor growth of a sub-collector layer, a collector layer, a base layer and an emitter layer in this turn on a compound semiconductor substrate using MOCVD method wherein the base layer is grown as a p-type compound semiconductor thin film layer containing at least one of Ga, Al and In as a Group III element and As as a Group V element under such growth conditions that the growth rate gives a growth determined by a Group V gas flow rate-feed.

Abstract: A compound semiconductor epitaxial substrate including a substrate, and a sub-collector layer, a collector layer, a base layer, an emitter layer and a contact layer(s) formed in this order on the substrate, the compound semiconductor epitaxial substrate having an oxygen-containing layer between the substrate and the sub-collector layer.

Abstract: A compound semiconductor epitaxial substrate for use in a strain channel high electron mobility field effect transistor, comprising an InGaAs layer as a strain channel layer 6 and AlGaAs layers containing n-type impurities as back side and front side electron supplying layers 3 and 9, wherein an emission peak wavelength from the strain channel layer 6 at 77 K is set to 1030 nm or more by optimizing the In composition and the thickness of the strain channel layer 6.

Abstract: A compound semiconductor epitaxial substrate having a pseudomorphic high electron mobility field effect transistor structure which comprises an InGaAs layer as a channel layer 9 and an InGaP layer containing n-type impurities as a front side electron supplying layer 12, wherein an electron mobility in the InGaAs layer at room temperature (300 K) has become 8000 cm2/V·s or more by growing an epitaxial substrate having a pseudomorphic HEMT structure with an In composition of the channel layer 9 increased. Front side spacer layers 10 and 11 between the channel layer 9 and the front side electron supplying layer 12 may also be InGaP layers.

Abstract: A method for producing a compound semiconductor wafer used for production of HBT by vapor growth of a sub-collector layer, a collector layer, a base layer and an emitter layer in this turn on a compound semiconductor substrate using MOCVD method wherein the base layer is grown as a p-type compound semiconductor thin film layer containing at least one of Ga, Al and In as a Group III element and As as a Group V element under such growth conditions that the growth rate gives a growth determined by a Group V gas flow rate-feed.

Abstract: A thin film crystal wafer with pn-junction comprising a first layer of a first conductivity type which is a 3-5 group compound semiconductor represented by a general formula: InxGayAlzP (0≦x≦1, 0≦y≦1, 0≦z≦, x+y+z=1), and the second layer of a first conductivity type which is a 3-5 group compound semiconductor represented by a general formula: InxGayAlZ,As (0≦x≦1, 0≦y≦1, 0≦z≦1, x+y+z=1), said second layer being made above said first layer, and at a heterojunction interface formed between said first layer and said second layer, further comprising a charge compensation layer of a first conductivity type with an impurity concentration higher than that of said first and second layers.

Abstract: A thin film crystal wafer with pn-junction comprising a first layer of a first conductivity type which is a 3-5 group compound semiconductor represented by a general formula: InxGayAlzP (0≦x≦1, 0≦y≦1, 0≦z≦, x+y+z=1), and the second layer of a first conductivity type which is a 3-5 group compound semiconductor represented by a general formula: InxGayAlZ,As (0≦x≦1, 0≦y≦1, 0≦z≦1, x+y+z=1), said second layer being made above said first layer, and at a heterojunction interface formed between said first layer and said second layer, further comprising a charge compensation layer of a first conductivity type with an impurity concentration higher than that of said first and second layers.

Abstract: A thin-film crystal wafer having a pn junction includes a first crystal layer of p GaAs, a second crystal layer of n InxAlyGa1-x-yP, the first and second crystal layers being lattice-matched layers that form a heterojunction, and a control layer of a thin-film of InxAlyGa1-x-yP differing in composition from the n InxAlyGa1-x-yP of the second crystal layer is formed at the interface of the heterojunction. The control layer enables the energy discontinuity at the interface of the InxAlyGa1-x-yP/GaAs heterojunction to be set within a relatively broad range of values and thus enables the current amplification factor and the offset voltage to be matched to specification values by varying the energy band gap at the heterojunction.

Abstract: The invention provides an electrode material having the low contact resistance against a III-V group compound semiconductor, thereby realizing a light emitting device having a high luminance and driven at low voltages. The electrode material of the invention is applied to a III-V group compound semiconductor, which is expressed as a general formula of InxGayAlzN, where x+y+z=1, 0≦x≦1, 0≦y≦1, and 0≦z≦1, and doped with p-type impurities. The electrode material comprises an alloy of Au and at least one metal selected from the group consisting of Mg and Zn.

Abstract: The invention provides an electrode material having the low contact resistance against a III-V group compound semiconductor, thereby realizing a light emitting device having a high luminance and driven at low voltages. The electrode material of the invention is applied to a III-V group compound semiconductor, which is expressed as a general formula of In.sub.x Ga.sub.y Al.sub.z N, where x+y+z=1, 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, and 0.ltoreq.z.ltoreq.1, and doped with p-type impurities. The electrode material comprises an alloy of Au and at least one metal selected from the group consisting of Mg and Zn.

Abstract: A process for crystal growth of III-V group compound semiconductor, which comprises pyrolyzing, in a gas phase, a material consisting of an organometallic compound and/or a hydride in the presence of an organic compound containing an oxygen atom-carbon atom direct bond, used as a dopant to grow a III-V group compound semiconductor crystal layer containing at least aluminum, of high electric resistance. Said process can grow a compound semiconductor layer of high electric resistance by the use of a dopant which enables the independent controls of oxygen concentration and aluminum concentration and which has a small effect of oxygen remaining.

Abstract: A semiconductor epitaxial substrate, characterized in that a crystal is formed by epitaxial growth on a gallium arsenide single crystal substrate whose crystallographic plane azimuth is slanted from that of one of {100} planes at an angle of not more than 1.degree., that at least part of the epitaxial crystal is an In.sub.x Ga.sub.(1-x) As crystal (wherein 0<x<1), and that the epitaxial growth is carried out by chemical vapor deposition. Since the In.sub.x Ga.sub.(1-x) As layer has reduced microscopic unevenness and reduced variation in thickness, the epitaxial substrate of the present invention can be used as a channel layer of a field effect transistor or as an active layer of a semiconductor laser to endow these devices with excellent characteristics.

Abstract: A semiconductor epitaxial substrate and a process for producing the same, the semiconductor epitaxial substrate comprising a GaAs single-crystal substrate having thereon an In.sub.y Ga.sub.(1-y) As (0<y.ltoreq.1) crystal layer as a channel layer, the composition and the thickness of the In.sub.y Ga.sub.(1-y) As layer being in the ranges within the elastic deformation limit of crystals constituting the In.sub.y Ga.sub.(1-y) As layer and the vicinity of the In.sub.y Ga.sub.(1-y) As layer, the semiconductor epitaxial substrate further comprising a semiconductor layer between the channel layer and an electron donating layer for supplying electrons to the channel layer, the semiconductor layer having a thickness of from 0.5 to 5 nm and a bandgap width within the range of from the bandgap width of GaAs to the bandgap width of the electron donating layer.

Abstract: An epitaxially grown compound-semiconductor crystal comprising a substrate, a buffer layer formed directly or indirectly on the substrate, and an active layer formed on the buffer layer. The buffer layer comprises (A) a high-resistivity AlGaAs or AlGaInP layer doped with oxygen or/and a transition metal and, formed thereon, (B) a layer consisting of high-purity GaAs, InGaP, or AlGaAs.

Abstract: A vapor-phase epitaxial growth method for producing a Groups III-V compound semiconductor containing arsenic by vapor-phase epitaxial growth using arsenic trihydride as an arsenic source is disclosed, wherein said arsenic trihydride has a volatile impurity concentration of not more than 1.5 molppb on a germanium tetrahydride conversion. The resulting epitaxial crystal has a low residual carrier concentration and is applicable to a field effect transistor.

Abstract: In an apparatus for vapor-phase growth which comprises a reactor having an inlet for the introduction of the gas containing a source material on its top and a susceptor provided in the downstream portion of the reactor, the improvement wherein the susceptor is generally in a conical or polygonal pyramid form consisting of an upper rectifying portion and a lower substrate holding portion, with the diameter of the susceptor in its lower portion increasing by a greater degree than in its upper portion.