Nippon Mining Co., Ltd.

Haruhito Shimakura

Osamu Oda

Keiji Kainosho

Manabu Kanou

A semi-insulating InP single crystal, semiconductor device with a substrate of crystal and processes of producing the same are disclosed. Crystal is derived from an undoped InP single crystal intermediate. The intermediate has a concentration of all native Fe, Co and Cr of 0.05 ppmw. The crystal has a resistivity of 1.times.10.sup.6 .OMEGA..multidot.cm or more and a mobility of above 3,000 cm.sup.2 /V.multidot.s both at 300K. A process of producing the crystal includes a step of heat-treating the intermediate under 6 kg/cm.sup.2 of phosphorus vapor pressure. The produced semiconductor device is a MIS device operating in essentially the same high-speed manner as a HEMT.

Semi-insulating InP single crystals, semiconductor devices having

Process for producing a uniform oxide layer on a compound semiconductor

A semi-insulating InP single crystal, semiconductor device with a substrate of crystal and processes of producing the same are disclosed. The crystal is derived from an undoped InP single crystal intermediate. The intermediate has a concentration of all native Fe, Co and Cr of 0.05 ppmw or less. The crystal has a resistivity of 1.times.10.sup.6 .OMEGA..multidot.cm or more and a mobility of above 3,000 cm.sup.2 /V.multidot.s both at 300 K. A process of producing the crystal includes a step of heat-treating the intermediate under 6 kg/cm.sup.2 of phosphorus vapor pressure. The produced semiconductor device is a MIS device operating in essentially the same high-speed manner as a HEMT.

Semi-insulating INP single crystals, semiconductor devices having

A method of producing a GaAs single crystal substrate comprises the steps of conducting a first-stage annealing by vacuum-sealing a GaAs single crystal wafer and arsenic in a heat-resistant vessel and heating the wafer to a temperature of 1050.degree. to 1150.degree. C. while exposing it to arsenic vapor pressure, cooling the wafer to room temperature at a cooling rate of 1.degree.-25.degree. C./min., removing the wafer from the vessel, etching the wafer and placing it in another vessel, conducting a second-stage annealing by heating the wafer to a temperature of 910.degree. to 1050.degree. C. in a non-oxidizing atmosphere, cooling the wafer to room temperature at a cooling rate of 1.degree.-25.degree. C./min., removing it from the vessel, etching the wafer, conducting a third-stage annealing by vacuum-sealing the wafer and arsenic in the heat-resistant vessel and heating the wafer to a temperature of 520.degree.-730.degree. C. while exposing it to arsenic vapor, and cooling the wafer at least down to 400.degree. C. at a cooling rate of 15.degree.-30.degree. C./min.

Method of producing GaAs single crystal substrate using three stage

The present invention relates to a method for producing InP single crystals containing impurities such as Fe, Co, Ti, Cr or the like by cutting the single crystals into wafers or blocks and heat-treating the cut wafers or blocks at temperatures ranging from 400.degree. C. to 690.degree. C. Further, the invention is related to a method for producing compound semiconductor devices employing Fe-doped InP single crystals as the substrate of the device. In this method, the InP single crystals are cut into wafers and the cut wafers are heat-treated at temperatures ranging from 400.degree. C. to 690.degree. C. Further, the wafers are implanted with ions and heat-treated at 690.degree. C. or lower to activate the implanted ions. These methods ensure to produce the single crystals and the compound semiconductor devices which have superior electrical properties.

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Toda, Japan

Haruhito Shimakura