Abstract: A semiconductor device includes a GaAs substrate having a lattice constant; and a III-V mixed crystal semiconductor layer disposed on the GaAs substrate, containing Tl (thallium) and Ga (gallium) as Group III elements and As (arsenic) as a Group V element, and having a lattice constant larger than the lattice constant of the GaAs substrate. Therefore, the lattice mismatch of the III-V mixed crystal semiconductor layer with GaAs and the band gap energy of the III-V mixed crystal semiconductor layer are smaller than those of an InGaAs layer, resulting in a semiconductor device with improved operating characteristics and reliability.

Abstract: A semiconductor light emitting device includes an Si substrate having opposed front and rear surfaces; an amorphous or polycrystalline first buffer layer disposed on the front surface of the Si substrate; and GaN series compound semiconductor layers successively disposed on the first buffer layer and including a light emitting region where light is produced by recombination of electrons and holes. In this light emitting device, since the Si substrate is cleavable, it is possible to produce resonator facets by cleaving. In addition, since the Si substrate is electrically conductive, a structure in which a pair of electrodes are respectively located on opposed upper and lower surfaces of the light emitting device is realized. Further, since the Si substrate is inexpensive, the light emitting device is obtained at low cost.

Abstract: A semiconductor device includes an Si substrate, a stress absorbing layer of GaAs and disposed on the Si substrate, a buffer layer having a composition of Al.sub.x Ga.sub.1-x-y In.sub.y N (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) and disposed on the stress absorbing layer, and a compound semiconductor layer having a composition of Al.sub.x Ga.sub.1-x-y In.sub.y N (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) and disposed on the buffer layer. Therefore, the buffer layer protects the GaAs stress absorbing layer from high temperatures during the formation of the compound semiconductor layer, whereby the stress absorbing layer is prevented from decomposition. As a result, a stress due to lattice mismatch or thermal stress between the Si substrate and the compound semiconductor layer is absorbed in the GaAs stress absorbing layer having a lowest bulk modulus, whereby a compound semiconductor layer with reduced dislocations may be grown on the buffer layer and bending of the Si substrate prevented.

Abstract: A method of fabricating a light emitting diode (LED) device producing visible light includes growing layers of an LED emitting blue light to form a blue LED; growing layers of an LED emitting green light to form a green LED; growing layers of an LED emitting red light to form a red LED; and uniting the three LEDs directly to each other by annealing. Therefore, an LED device that can emit light of all three colors from the same region of the LED device with variable light intensity is obtained.

Abstract: A semiconductor laser includes an electrically insulating substrate having an opening; a first conductivity type first contact layer within the opening; a laminated semiconductor layer structure on the first contact layer and comprising a first cladding layer, an active layer, a second cladding layer, and a second contact layer wherein the first contact layer includes an aperture within the opening; a first electrode disposed on the electrically insulating substrate and extending to and contacting the first contact layer; and a second electrode in electrical contact with the second contact layer. The substrate is preferably sapphire, MgO, and spinel and the semiconductor layers are preferably GaN materials so that the laser emits short wavelength light. An electrode makes direct, reliable contact to the first cladding layer through an opening in the electrically insulating substrate without the need of mechanically working or etching the substrate.

Abstract: A material supplying apparatus includes a container for storing a solution; an inlet pipe for introducing a carrier gas and an outlet pipe; electrodes disposed in the container over the depth direction of the container and forming a capacitor; and apparatus for calculating a residual amount of the solution in the container from the capacitance of the capacitor formed by the electrodes. The solution is used as the dielectric of the capacitor formed in the container and the capacitance varies according to the quantity of solution so that the residual amount of the solution and the time to replenish the solution are calculated in a simple structure having no moving parts.

Abstract: A semiconductor light emitting element includes a wide band gap energy II-VI semiconductor layer on a p type III-V semiconductor substrate and a III-V semiconductor buffer layer between the semiconductor substrate and the wide band gap energy II-VI semiconductor layer having a band gap energy intermediate those of the semiconductor substrate and the wide band gap energy II-VI semiconductor layer. Energy spikes in the valence band of the element are reduced and the injection efficiency of holes is increased so that a semiconductor light emitting element having a low operation voltage is produced.

Abstract: A method for producing a photo-voltaic infrared detector including growing a crystalline CdHgTe layer on a CdTe substrate by liquid phase epitaxy using a growth melt including tellurium as a solvent to which indium is added as a dopant impurity in a concentration of from 0.01 to 0.1 ppm; annealing the CdHgTe layer to produce a p-type CdHgTe layer including indium as an n-type background dopant impurity; forming an n-type region of a desired depth as a light receiving region at the surface of the p-type CdHgTe layer by implanting a dopant impurity producing n-type conductivity and annealing; and forming an n-side electrode on the n-type region and a p-side electrode a prescribed distance from the n-type region on the p-type CdHgTe layer.