Semiconductor devices and methods of manufacturing same
AssigneeKabushiki Kaisha Suwa Seikosha
InventorsHiroshi Harigaya, Toshio Kano, Eishi Aizawa
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Abstract
A gate self-alignment type field-effect semiconductor device is formed with an insulating film deposited on the surface of a substrate. A polycrystal silicon doped with impurities having a type of conductivity opposite to the conductivity of the substrate extends through a gap in said insulating film to engage the surface of said substrate so as to serve as both a diffusion source and electrode for each of the source and drain of the device.
Claims18
A method of forming an insulated gate type field-effect semiconductor device comprising forming a first insulating film on the surface of a silicon substrate;
- removing a region of said first insulating film corresponding to the source, drain and gate regions of the semiconductor device to be formed;
- forming a layer of polycrystal silicon doped with impurities having a type of conductivity opposite to that of said substrate on the exposed surface of said substrate and said first insulating film;
- forming a second insulating film on the surface of said polycrystal silicon;
- removing portions of said second insulating film and said polycrystal silicon at least in the region surrounding the region thereof adjacent the source, drain and gate regions of said substrate and in registration with the desired gate region of said substrate;
- forming a gate insulating film on the exposed surface of said substrate defining said gate region;
- forming said source and drain regions using said polycrystal silicon layer as a diffusion source;
- forming apertures in said second insulating film providing access to the two portions of said polycrystal silicon layer associated respectively with said source and drain;
- and forming electro-conductive elements, one of said elements extending through each of said apertures in said second insulating film for respectively engaging each of said polycrystal silicon layer portions and a further of said elements engaging said gate insulating film.
A method for forming an insulated gate type field-effect semiconductor device consisting of forming a layer of a first insulated film on a silicon substrate;
- removing a region of said substrate corresponding to the source, drain and gate region of the semiconductor device to be formed;
- depositing a layer of polycrystal silicon doped with impurities which have a type of conductivity opposite to that of said substrate on the exposed surface of said substrate and first insulating layers;
- removing at least the region of said polycrystal silicon surrounding the region immediately adjacent said source, drain and gate region;
- forming a second insulating film layer on the exposed surface of said first insulating film and said polycrystal silicon;
- removing the central portion of said second insulating film and polycrystal silicon in registration with said gate region;
- forming a gate insulating film on the thus-exposed surface of said substrate;
- forming a source and a drain by diffusion from said polycrystal silicon portions;
- forming apertures in said second insulating film to expose a portion of the surface of each of said polycrystal silicon portions;
- and forming electro-conductive elements, one of said elements extending through each of said apertures for respective engagement with each of said polycrystal silicon elements, one of said elements engaging said gate insulating film.
Dependencies are inferred from the claim text.