Method for fabricating semiconductor devices
AssigneeKabushiki Kaisha Daini Seikosha
InventorMasafumi Shimbo
Life of this patent
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Abstract
A method of fabricating a semiconductor device comprising forming an island-shaped multi-layered structure of oxides and nitrides on the surface of a semiconductor. The multi-layered structure is selectively etched to define diffusion windows for forming a semiconductor structure in the semiconductor surface having a central region of one conductivity type surrounded by another region of a different conductivity type. A second island-like multi-layered structure is formed and is etched for controlling the duration of the etching steps by controlling the amount that the masks lift off from the insulation layers subjected to etching. The etching is carried out by side etching.
Claims7
A method for fabricating a semiconductor device, comprising the steps of:
- forming a multi-insulation layer composed of at least two kinds of materials including an anti-oxidation substance and an oxide on a semiconductor surface region of low impurity density in the form of an island;
- forming a first selective oxidation film on the surface of said low impurity density region by using at least one layer of said multi-insulation layer as a mask;
- defining a first window with a width determined by at least one side face of said multi-layer which has been subjected to side etching and an end portion of said first selective oxidation film and forming a first region of high impurity density in said semiconductor surface along the periphery of said island-like multi-insulation layer by selectively diffusing an impurity;
- forming the anti-oxidation insulation layer of said multi-insulation layer so as to reduce the size thereof after an insulation layer which is not a most upper layer and which is at least one layer of said multi-insulation layer is subjected to a second side etching and carrying out selective oxidation;
- and
- forming a second region of high impurity density in the inside of said first region after removing said multi-insulation layer and defining a window.
Dependencies are inferred from the claim text.