Garfin ƙofa

A cikin na'urorin lantarki, ƙarfin ƙofa shine ƙarfin tashar ƙofar transistor na tasirin filin (FET). Ana iya bayyana shi azaman cikakken ƙarfin ƙofar transistor, ko azaman ƙarfin kowane yanki na fasahar da'ira mai haɗawa, ko azaman ƙarfin kowane faɗin na'urar transistor mai ƙarancin tsayi a cikin fasaha.

A cikin tsararraki na kimanin sikelin Dennard na ƙarfe-oxide-semiconductor FETs (MOSFETs), ƙarfin kowace yanki ya ƙaru da bambanci da girman na'urar. Tunda yankin ƙofar ya faɗi da murabba'in girman na'urar, ƙarfin ƙofar transistor ya faɗi daidai gwargwado tare da girman na'urar. Tare da sikelin Dennard, ƙarfin kowace sashi na faɗin ƙofar ya kasance kusan daidai; wannan ma'aunin zai iya haɗawa da ƙarfin ƙofa-tushen da ƙarfin overlapse na ƙofa-magudanar ruwa. Sauran sikelin ba sabon abu bane; ƙarfin lantarki da kauri na ƙofa oxide ba koyaushe suke raguwa da sauri kamar girman na'urar ba, don haka ƙarfin ƙofa a kowane yanki bai ƙaru da sauri ba, kuma ƙarfin kowace faɗin transistor wani lokacin yana raguwa tsawon tsararraki. 

Ana iya ƙididdige ƙarfin ƙofar da ke cikin ciki (wato, yin watsi da filayen fringing da sauran cikakkun bayanai) na ƙofar da ke da rufin silicon-dioxide daga ƙarfin thinner-oxide a kowane yanki kamar haka:



inda: 

 AG is the gate area
  is the thin-oxide capacitance per unit area, where 
 εSiO2 = 3.9 is the relative permittivity of silicon dioxide
 ε0 = 8.854×10−12 F/m is the vacuum permittivity
 tox is the oxide thickness.

 Nassoshi