Fully CMOS-type SRAM device and method for fabricating the same

Claim 1

A method for fabricating a static random access memory device, comprising the steps of: forming, on a main surface of a semiconductor substrate, driver MOS transistors of a first conductivity constituting driver transistors of a flip-flop memory cell, and transfer MOS transistors of said first conductivity having sources connected with drains of said driver MOS transistors; forming, on said driver and transfer MOS transistors, a first insulating film, a conductive thin film, and a second insulating film; selectively etching said second insulating film, said conductive thin film and said first insulating film to form first and second contact hole portions exposing surfaces of storage nodes of said flip-flop memory cell and surfaces of the drains of said transfer MOS transistors respectively; forming side walls made of an insulating material on inner walls of said first and second contact hole portions to form first and second contact holes on said storage nodes and the drains of said transfer MOS transistors, respectively; forming MOS thin film transistors of a second conductivity constituting load transistors of said flip-flop memory cell, connected with the said storage nodes through said first contact holes; forming drawing electrodes connected with the drains of said transfer MOS transistors through said second contact holes; and forming bit lines connected with said drawings electrode, respectively.

Claim 2

A method for fabricating a static random access memory device, comprising the steps of: forming, on a main surface of a semiconductor substrate, driver MOS transistors of a first conductivity constituting driver transistors of a flip-flop memory cell, and transfer MOS transistors of said first conductivity having sources connected with drains of said driver MOS transistors; forming, on said driver and transfer MOS transistors, a first insulating film, a conductive thin film, and a second insulating film; selectively etching said second insulating film, said conductive thin film and said first insulating film to form first and second contact hole portions exposing surfaces of storage nodes of said flip-flop memory cell and surfaces of the drains of said transfer MOS transistors respectively; forming side walls made of an insulating material on inner walls of said first and second contact hole portions to form first and second contact holes on said storage nodes and the drains of said transfer MOS transistors, respectively; forming MOS thin film transistors of a second conductivity constituting load transistors of said flip-flop memory cell, connected with the said storage nodes through said first contact holes; forming drawing electrodes connected with the drains of said transfer MOS transistors through said second contact holes; and forming bit lines connected with said drawings electrode, respectively.