Abstract: There is disclosed a method for producing an epitaxial wafer with a buried diffusion layer comprising: implanting an impurity into a silicon single crystal wafer; subsequently diffusing the impurity in the wafer to form a diffusion layer; at least removing an oxide film on the diffusion layer; and thereafter forming a silicon epitaxial layer over the wafer to produce a silicon epitaxial wafer with a buried diffusion layer; wherein at least the oxide film on the diffusion layer is removed by etching with hydrofluoric acid to which a surfactant is added, and then the silicon epitaxial layer is formed. There can be provided a method for producing an epitaxial wafer with a buried diffusion layer in which generation of crystal defects in a silicon epitaxial layer is reduced effectively and an epitaxial wafer with a buried diffusion layer.

Abstract: There is disclosed a method for producing an epitaxial wafer with a buried diffusion layer comprising: implanting an impurity into a silicon single crystal wafer; subsequently diffusing the impurity in the wafer to form a diffusion layer; at least removing an oxide film on the diffusion layer; and thereafter forming a silicon epitaxial layer over the wafer to produce a silicon epitaxial wafer with a buried diffusion layer; wherein at least the oxide film on the diffusion layer is removed by etching with hydrofluoric acid to which a surfactant is added, and then the silicon epitaxial layer is formed. There can be provided a method for producing an epitaxial wafer with a buried diffusion layer in which generation of crystal defects in a silicon epitaxial layer is reduced effectively and an epitaxial wafer with a buried diffusion layer.

Abstract: An openable dome-shaped roof structure is provided upon a circular side wall and comprises a crescent-shaped fixed roof section, a pair of pivotable roof sections and a pair of slidable roof sections. Each pivotable roof section is connected to a respective slidable roof section by a pivot at peripheral end portions thereof so that the pivotable roof section can rotate to a position above the slidable roof section. The slidable roof sections are each provided to be able to rotate toward the upper surface of the fixed roof section about the center of the circle of the side wall.