Abstract:
PURPOSE:To make it possible to conduct optical measurement of an object by turning its required region into a multi-crystal in such a manner that an insulator is formed on the required region on a base plate prior to formation of an epithaxial layer. CONSTITUTION:An insulator layer (e.g. an approimately 500Angstrom thick film 5 of SiO2) is formed on a required region on the top surface of a base plate 4 made of such a material as phosphoric silicon. And then, an n type epithaxial layer 6 is formed. At this time, although the n type epithaxial layer 6 on the region free of SiO2 film is a single (or mono) crystal, the n type epithaxial layer 7 on the SiO2 layer is to become a multi-crystal. Now, the multi-crystal n type epithaxial layer 7 is selectively removed by using a mixed solution of fluoric acid and nitric acid. And then, the SiO2 film is removed by using fluoric acid. Now, measurement is made on difference in height between thus exposed surface of the phosphoric silicon base plate 4 and the surface of the single- (or mono-) crystal n type epithaxial layer 6.
Abstract:
PURPOSE:To lower a contact resistance and reduce irregularity by using electrode materials including Ga in electrode materials by which the ohmic contact to GaAs is formed. CONSTITUTION:Au, Ge and Ga 2 are evaporated on n-type GaAs 1, which has the surface smoothed by mechanical and chemical methods and has a carrier density of n 10 cm , by the vacuum evaporation method and are subjected to heat treatment in an inactive gas atmosphere, thereby forming alloy layer 2'.
Abstract:
PURPOSE:To obtain a high-performance JFET by forming a buried layer through ion injection method within the island region to isolate substantially the island region into the surface layer and the channel in the state under which the surface density of the island region is kept high.
Abstract:
PURPOSE:To ensure a heat treatment without any composition change and exfoliation by avoiding the adverse diffusion from the compound semiconductor and at the same time by forming a protective film featuring nearly identical heat expansion coefficient to the compound semiconductor.
Abstract:
PURPOSE:To enable easy observation by optical microscope, by coloring the cracked layer developed in the base, thru the immersion of GaAs mono crystal base in the mixture taking fluorine acid as major component.
Abstract:
PURPOSE:To form good ohmic contact by ion implanting more than one structural components and making heat treatment in the case of metals or alloys forming ohmic contact beforehand within a semiconductor.
Abstract:
PURPOSE:To protect substrate surface from contamination owing to photoetching and prevent the deterioration in characteristics by performing impurity diffusion from the exposed gap under overhangs in the double insulation layer on the substrate.
Abstract:
PROBLEM TO BE SOLVED: To provide a highly reliable buildup wiring board in which the diameter at the bottom of a via formed in a buildup layer can be made substantially uniform. SOLUTION: In the buildup wiring board comprising a core substrate 11 having a via 12 formed in the insulating layer and filled with conductive paste 13 for interlayer connection, and a buildup layer 14 formed at least on one side of the core substrate 11 and having a via 15 for interlayer connection, the diameter at the bottom of the via 15 formed in the buildup layer 14 is made substantially uniform. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a buildup wiring board exhibiting high heat dissipation properties by touching a metal layer of the through hole of a core layer to a metal layer of the via of a buildup layer. SOLUTION: In the buildup wiring board comprising a core substrate 4 having a via 2 formed in an insulating layer 1 and filled with conductive paste 3 for interlayer connection, and a buildup layer 5 formed at least on one side of the core substrate 4 and having a via 8 for interlayer connection, the via 2 filled with the conductive paste 3 for interlayer connection is formed in each insulating layer 1 of the core substrate 4, a through hole 6 penetrating all layers of the core substrate 4 is formed, and the via 8 formed in the buildup layer 5 and the through hole 6 are made contact through metal layers 7 and 9 formed, respectively. COPYRIGHT: (C)2008,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a thin-layered multilayer circuit board by solving the problem that a conventional multilayer circuit board using a plurality of films as insulating layers connects the films together via an adhesive may lead to a case, where the adhesive affects an effort for providing a thin-layered multilayer circuit board. SOLUTION: A plurality of double-face boards 114a, 114b using films 102a, 102b are pasted together via a paste connecting layer 116, with conductive paste 126 filled and cured in through-holes 124 formed on a temporary-cured resin 120. The curing conductive paste 126 filling the through-holes 124 preformed on the paste connecting layer 116 connects second hardwire 106a and 106b electrically, thus providing a thin-layered multilayer printed circuit board without using an adhesive. COPYRIGHT: (C)2007,JPO&INPIT