Abstract: A method for producing a semiconductor device comprises the steps of: preparing a III.sub.b -V.sub.b group compound single crystalline semiconductor substrate produced by a liquid encapsulated Czochralski process, the single crystalline semiconductor substrate having a carbon concentration of 1.times.10.sup.15 cm.sup.-3 or less, implanting conductive impurity ions into the single crystalline semiconductor substrate and then annealing, and a semiconductor device produced by this method.

Abstract: In an epitaxial wafer comprising of a single crystalline substrate, a p type gallium aluminum arsenide mixed crystalline layer and n type gallium aluminum arsenide mixed crystalline layer having an indirect transition type band structure. The p type gallium aluminum arsenide mixed crystalline layer consists of a gallium aluminum arsenide mixed crystalline layer having a direct transition type band structure, positioned about 3 to 10 .mu.m from the pn junction and a gallium aluminum arsenide mixed crystalline layer having an indirect transition type band structure. The aluminum arsenide mixed crystal ratio in the gallium aluminum arsenide is exponentially and gradually changed in the region between the direct transition type layer and the indirect transition type layer.

Abstract: A substrate for a high-intensity LED and the method of epitaxially growing the substrate according to the invention are based on the fact that, in using an AuZn alloy or the like as the ohmic electrode of the p-type Al.sub.x Ga.sub.1-x As layer (2), the higher the carrier concentration of this layer, the smaller the contact resistance and the lower the applied voltage (V.sub.F) necessary for passing a forward current of 10 mA. Joint use is made of gas-phase epitaxy and liquid-phase epitaxy. A layer having a carrier concentration three to five times that of an epitaxial layer formed by liquid-phase epitaxy (LPE) can be realized with excellent reproducibility by gas-phase epitaxy (MOCVD process, MBE process, etc.). By utilizing this p-type Al.sub.x Ga.sub.1-x As layer (2) as an electrode contact layer, contact resistance can be reduced and variance diminished.

Abstract: In the boat growth method of the IIIb-Vb group compound, the quartz boat is tridymitized on at least the surface thereof so as to prevent wetting of the boat due to the melt of the compound and hence to enhance the yield of a single crystal.

Abstract: An epitaxial wafer for producing arrays of GaAsP-LEDs comprises, in the GaAs.sub.1-x P.sub.x layer with varying X, a layer region(s) with a discontinuous variance of x along the thickness of the GaAs.sub.1-x P.sub.x layer. This layer region(s) contribute to a uniformity in the brightness of the light emission of LEDs formed in the epitaxial wafer.

Abstract: In a GaAs epitaxial wafer including, for example, two epitaxial layers having high and low carrier concentrations, the carrier concentration of the low carrier concentration layer is liable to greatly vary, so that wafers suitable for FETs and Schottky barrier diodes operated at UHF and SHF are produced at only a low yield. This drawback is eliminated by adjusting the heating temperature of GaAs substrate to 690.degree. to 730.degree. C. during the growth of the low carrier concentration layer.

Abstract: Biaxially drawn polyamide films having an excellent levelness are prepared as follows. A substantially unoriented polyamide film is heated at 45.degree.-65.degree. C., and then drawn in the longitudinal direction at a deformation rate of at least 10,000%/min. and a draw ratio of 2.7-3.5 by a roll stretcher. The drawn film is immediately transferred to the lateral drawing position at 45.degree.-60.degree. C. within a time (t):t=e.sup.(3.9-0.053T.sbsp.1.sup.) where e=the base of natural logarithm and T.sub.1 =film temperature during this period of time (t), which is 45.degree.-60.degree. C. The thickness profile of the film at the starting position of lateral drawing is gradually reduced from the side and portions toward the central portion of the width so that the film thickness at the central portion is 75-90% of the film thickness at the side end portions. The film is drawn in the lateral direction at an average deformation rate of 2,000-10,000%/min.

Abstract: The reproducibility of Te doping in III-V group compounds is improved by using as the dopant a III-V group compound containing Te at a concentration of at least 1.times.10.sup.17 cm.sup.-3.

Abstract: A heat resistant resin composition comprising from 10 to 90% by weight of a copolymer A and from 90 to 10% by weight of a copolymer B, in which the copolymer A is composed of an N-aromatic maleimide monomer residue, a maleimide monomer residue, a vinyl aromatic monomer residue and, optionally other vinyl monomer residue, the total content of the N-aromatic maleimide monomer residue and the maleimide monomer residue being from 10 to 45%, the content of the N-aromatic maleimide monomer residue being greater than the content of the maleimide monomer residue, the content of the vinyl aromatic monomer residue being from 90 to 55% and the content of said other vinyl monomer residue being from 0 to 20%, and the copolymer B is composed of a vinyl cyanide monomer residue, a vinyl aromatic monomer residue and, optionally other vinyl monomer residue, the content of the vinyl cyanide monomer residue being from 20 to 55%, the content of the vinyl aromatic monomer residue being from 80 to 45% and the content of said other

Abstract: The present invention relates to a wafer for use in the production of an infrared LED. Conventionally, infrared LEDs are produced by using an epitaxial wafer comprising P- and N-type GaAs epitaxial layers. The wafer according to the present invention is characterized by having a P-type Ga.sub.1-x Al.sub.x As epitaxial layer and improves the output power of infrared LEDs. The epitaxial layers according to the present invention are (1) a 20-100 .mu.m thick N-type GaAs epitaxial layer consisting of N-type GaAs doped with Si and having a carrier concentration in the range of from 1.0.times.10.sup.17.cm.sup.-3 to 2.0.times.10.sup.18.cm.sup.-3, (2) a 10-80 .mu.m thick P-type GaAs epitaxial layer consisting of P-type GaAs doped with Si and having a carrier concentration in the range of from 1.0.times.10.sup.17.cm.sup.-3 to 5.0.times.10.sup.18.cm.sup.-3, and (3) a 5-90 .mu.m thick mixed crystal layer consisting of P-type Ga.sub.1-x Al.sub.x As mixed crystal and having a carrier concentration of from 1.0.times.10.sup.

Abstract: An epitaxial wafer of a compound semiconductor comprising a single crystalline semiconductor substrate consisting of GaP and an active layer consisting of GaAs.sub.1-x P.sub.x, having a mixed crystal ratio (x) in the range of from 0.5 to 1 is used for an LED. According to the present invention, between the single crystalline semiconductor substrate and the active layer, a light-absorbing layer consisting of GaAs.sub.1-x P.sub.x having the mixed crystal ratio (x) smaller than that of the active layer, is formed to suppress the reflection of light from the surface of the substrate.

Abstract: When the growth of a single crystalline III.sub.b -V.sub.b group compound is carried out employing the horizontal Bridgeman method or the gradient freeze method, it is likely that polycrystals will be grown, crystal defects will form, and the distribution of impurities will not be uniform, especially if the diameter of the single crystal is large. In the present invention, the cooling rate of the melt is controlled in an inconstant manner. Namely, crystal growth is interrupted at least once and/or the cooling rate at an earlier growth period is controlled at a high value. From 40 to 65% of the total melt crystallizes at the time when 30% of the total time required for growth has elapsed. The high yield of a single crystal is attained according to the present invention.

Abstract: A method of manufacturing a mixed crystal compound semiconductor wafer suitable for the production of LED having a high light output. Upon a monocrystalline substrate of III-V semiconductor material a base layer is epitaxially grown of the same material as the substrate. An initial gradient layer is grown on the base layer having a mixed crystal ratio varying continuously from that of the base layer to a first value at a constant temperature. A combination sublayer is grown on the initial gradient sublayer which includes at least one constant sublayer having a constant crystal mixture ratio and at least one gradient sublayer having a crystal mixture ratio varying continuously between the mixed crystal ratios of its adjacent constant layers.

Abstract: An epitaxial wafer of GaAs.sub.1-x P.sub.x has been doped with nitrogen and used for the production of light emitting diode (LED). The carrier concentration of the conventional GaAs.sub.1-x P.sub.x was from 3.times.10.sup.16 to 2.times.10.sup.17 /cm.sup.3.According to the present invention, the carrier concentration is reduced lower than the conventional concentration and the luminance of LED is increased approximately two or three times the conventional luminance.

Abstract: Semiconductor epitaxial wafers consisting of an epitaxial film and its substrate can be removed, in accordance with the present invention, from a substrate supporting component, without breaking the wafers into pieces after completion of vapor growth. The carbonaceous powder according to the present invention can greatly and effectively decrease the breaking of wafers, as compared with the conventional SiO.sub.2 or SiC-coated substrate supporting components.