Amorphousdevices: atthethreshold After 15years ofcontroversy, these unconventional devices areentering commercial competition
Gerald Lapidus · 1973
Since itsinception inthelate 1950s anditsformalnoise-immune threshold switches andlogic circuits, introduction sometenyears later, amorphous technology optical massmemories, anddry-process silverless photo- hasinstigated heated debate inthesemiconductor in- graphic films. Butalthough devices havealready been dustry andhascreated anearlegend onWallStreet.built ordesigned forall ofthese areas, theonly products Now,after years oftrying toconvince theworldthat nowbeing marketed arenonvolatile read-mostly mem- there iscommercial substance tothis offbeat approach,ories (read-write memories usedmainly intheread Stanford R.Ovshinsky andhisdedicated followers at mode) andwet-process silverless graphic artsfilms. EnergyConversion Devices areundergoing theulti- Inalllikelihood, amorphous semiconductors will not, matetest: themarketplace. Thearguments aboutre- asisoften assumed, replace conventional semiconductors liability andreproducibility maysoonbesettled and formostapplications. Instead they aredirected touses amorphous materials canattempt tofulfill high expecta-forwhich transistors maynotbesuitable atthepresent tions innonvolatile memories, radiation-hard andhighlytime. Expected soonistheintroduction ofadry-process film. Alsounderwayaredevelopment programs bya numberofcompanies that areleaders intheir respective fields, aswellasbyGovernment agencies, whichcould 1.Applying theproperties ofamorphous materials