FILAMENT-TYPE MEMORY SEMICONDUCTOR DEVICE AND METHOD OF MAKING THE SAME

摘要

FILAMENT-TYPE MEMORY SEMICONDUCTOR DEVICE AND METHOD OF MAKING THE SAME : An improved memory device to be used in a D.C. curcuit which device includes a pair of spaced electrodes between which extends a body of a generally amorphous high resistance memory semiconductor material made of a composition of at least two elements and wherein the application to the electrodes of one or more set voltage pulses in excess of a given threshold level produces a relatively low resistance filamentous path comprising a deposit of at least one of said elements in a crystalline or relatively ordered state. When one or more D.C. current reset pulses of a given value and duration are fed through the filamentous path, the crystalline deposit is returned to a relatively disordered state and the more electropositive element of said composition normally tends to migrate to the negative electrode and the more electronegative element thereof normally tends to migrate to the positive electrode. The improvement is that the amorphous memory semiconductor in the fabrication thereof is provided adjacent substantially the entire surface area thereof facing one of the adjacent electrodes an electrode-memory semiconductor interface region containing a substantially higher concentration of said element which would normally tend to migrate . thereto during said reset operation, such electrode-memory semiconductor interface region being sufficiently extensive and having a sufficient concentration of said element to effect a stabilized gradient of said element through the reset region of the semiconductor material in at most a small number of set-reset cycles, so that threshold voltage stabilization is achieved substantially immediately thereafter.