Showing papers on "Gallium nitride published in 1984"

Manufacture of gallium nitride semiconductor device

Abstract: PURPOSE:To enable the formation of electrodes to the lower GaN layer by forming an apertuer in the surface GaN layer by a method wherein two or more of GaN layers are formed on a substrate, and a protection film is formed on the surface; next, an aperture is formed in the protection film, and heat treatment is carried out in a gas atmosphere containing hydrogen chloride gas. CONSTITUTION:An N type GaN layer 2 and a P type GaN layer 3 of insulation or high resistivity are formed on a sapphire substrate 1, and an Si dioxide film 10 is deposited on the GaN layer 3 of the outermost surface. Using this Si dioxide film 10 as the protection mask member, after an aperture is selectively provided thereto, heat treatment is carried out at 500 deg.C with flows of the mixed gas of AR and HCl, when the GaN layer 3 of the outermost surface exposed to this aperture is removed; accordingly, the lower GaN layer 2 is exposed. Next, the Si dioxide film 10 the protection film is removed; thereafter, an Al film is formed by evaporation and patterned into the first electrode layer 4 and the second electrode layer 11.

Gallium nitride semiconductor device

Abstract: PURPOSE:To form electrodes easily onto the upper surface and lower surface of a GaN semiconductor device by shaping GaN semiconductor devices onto both surfaces of the GaN crystal layer peeled from an insulating crystalline board for growth as the electrodes. CONSTITUTION:An AlN layer is grown onto a sapphire substrate, an n type GaN layer is further grown, and an insulating GaN layer is further grown. When a wafer grown in this manner is dipped in a boiling acidic solution or alkaline solution, only AlN is dissolved and removed selectively. Metallic films are formed onto the upper surface and lower surface of the GaN layer obtained in this manner, and patterned to shape electrodes 4, 10. The lower surface electrodes 10 and a metallic stem 9 are connected electrically, and the upper electrode 4 is connected through a wire bonding technique by using a metallic small- gage wire 5.

Growth of gallium nitride

Abstract: PURPOSE:To enable to obtin a GaN epitaxial layer of 30mum thickness or more having crystallizability of superior quality without generating exfoliation from a substrate by a method wherein growth of the GaN crystal is attained by performing the MOCVD method having small stress at the interface at the first stage, and by performing the CVD method to obtan crystallizability of superior quality at the second stage CONSTITUTION:A sapphire single crystal substrate 4 on a carbon susceptor 3 is heated at 950 degC according to a high-frequency induction heating coil 2 on the outer peripheral part of a quartz reaction tube 1 having a tube wall cooled by passing cooling water, TMG, H2, NH3 are supplied respectively from pipings 5, 6, 7 to make a vapor phase reaction to be performed, and a GaN crystal layer of 5mum thickness is obtained on the substrate 4 Then the GaN crystal layer 14 grown according to the MOCVD method on the tip of a control bar 13 is heated to 950 degC according to a heater 12 on the outer peripheral part of a quartz reaction tube 11, and NH3 and N2 are supplied from pipings 16, 17 Moreover, GaCl formed by introducing HCl from piping 18, and by making to react with Ga15 heated to be held at 850 degC is supplied, and a vapor phase reaction is made to be performed to obtain a GaN epitaxial layer of 30mum thickness in all on a substrate 14

Growing method of gallium nitride

Abstract: PURPOSE:To obtain a grown layer which has good surface flatness and crystallinity by performing the step of forming GaN on a crystalline substrate by the first step of executing in an inert atmosphere and the second step of performing in a hydrogen atmosphere. CONSTITUTION:The step of forming GaN on a crystalline substrate 4 is performed by the reaction of organic gallium compound with ammonia. In this case, the step is performed by the first step of executing in an inert atmosphere and the second step of performing in a hydrogen atmosphere. Organic gallium compound is selected from trimethyl gallium or triethyl gallium. Thus, a colorless, transparent, smooth-surface GaN crystalline layer is obtained on the substrate 4.

Manufacture of film of gallium nitride single crystal

Abstract: PURPOSE:To obtain a high quality film of a GaN single crystal, by growing a film of an AlN single crystal on a sapphire substrate and by forming a film of a GaN single crystal on the AlN film. CONSTITUTION:Molecular beams of Al from an Al evaporating source 6 and NH3 from a gas introducing pipe 5 are simultaneously fed to a sapphire substrate 4 heated to 1,000-1,200 deg.C in a vessel 1 evacuated to a superhigh degree of vacuum to form a film of an AlN single crystal. The feed of the beams is then stopped, the temp. of the substrate 4 is dropped to 600-700 deg.C, and molecular beams of Ga from a Ga evaporating source 7 and NH3 from the pipe 5 are simultaneously fed to the substrate 4 to form a film of a GaN single crystal on the AlN film on the substrate 4.