Abstract: An information retention capability based on a memory cell which comprises a pair of nonvolatile memory elements in a differential form is improved. A nonvolatile memory element (130) constituting a flash memory is so constructed that its tunnel oxide film (GO3) and floating gate electrode (FGT) are respectively formed by utilizing the gate oxide film (GT2) and gate electrode (GT2) of a transistor for a circuit which is formed on the same semiconductor substrate as that of the element (130). A memory cell is constructed in a 2-cells/1-bit scheme in which a pair of nonvolatile memory elements can be respectively connected to a pair of complementary data lines, and threshold voltage states different from each other are set for the nonvolatile memory elements so as to differentially read out data.

Abstract: The silicon substrate in which mesa semiconductor elements are formed is scribed along dicing lines by a laser. The resolidified silicon, which failed to vaporize during scribing, is etched away by sodium hydroxide solution. As a result, the silicon substrate is separated into a plurality of mesa semiconductor pellets. These pellets undergo chemical etching with a fluoric and nitric acid mixture to smooth the cut surfaces.

Abstract: A semiconductor rectifier device includes a heat-radiating substrate, a flame-sprayed insulating layer formed directly on a surface of the substrate, at least one first flame-sprayed metal layer selectively formed on the surface of the radiation substrate, and a second metal layer selectively formed on the flame-sprayed insulating layer. A rectifying circuit has first and second rectifying elements which are electrically coupled, respectively, at terminals of opposite polarities, with the first flame-sprayed metal layer and the second flame-sprayed metal layer. An electrode electrically connects the terminals of the rectifying elements having polarities opposite to those of the terminals connected to the first and second flame-sprayed layers.