Browsing by Author "G/Mariam, mebratu"

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    Experimental Study of Charge Distribution in Metal Oxide Semiconduc for (Mos) Structure
    (Addis Ababa University, 1990-06) G/Mariam, mebratu
    1~heprotical l.~[;VieVl O.i! MOS ntx'l!cture l.B done. Ideal NOS 'S::.t'uct".Ul:e HiHl cOrlsidm:od :arst. After it variuus eifedt:5 8uci! as wOl'k func'cion difference~ " oxide chaY.'ges etc, thllt deviute the ideal MOS property are cU s'~ussed. ~~hree eJ.0ci:r1cal me«flurell1elll: techniques are dlSCUUt;0U. 'I'he capacitance meD.sUrt!)ment technique at room temperature is used for the experiment. Desc:dpt:!.on of the experimentd. set up is glven and properties of indi vi-dual :l.ns·~'Cuments :l.ncluding the con1f)uter are dl.·!;;cnssed. Measurement :I.s done on th~,:en samples. Insulatinq 1<'>1er on samples 6f and th :1.6 [!$'02' on sample 120 t"le layer is lndl\'u",l - 1'h:tn - O;;ido 0 From high f.'cequency a-v measnrHinent: Rurf<.'ce charge density and t.m:face si:t.ta donsity 18 de"carmi.ned and thelr value :Ls COlUJ;lFll'ed 11i th data prev.iottd.y published. From " , combi.ned high and low frequency capacitance measurement values of anergy distribution of density of fltates and ~. ,I doping prof~"le are obtained. On all samples the' effect of; i:t}.moin?tion \?as observed in depletion and inversion layers. Distil~ct deviation from theoretically predicted h:l.gh f1'nqu~mcy c-v ct:rv()s WllS observed on sample 12<:. TI\'o peak appears bet.ween accumulation and depletion laye):. ~;hese peaks 8>:t' ,at bias value - Q,95v and ': o.:';::v. 'Ii", o~"as value are :i.l'!dependent of frequency.' The capacitance values of the peaks dec).'ease wH.h frequency .