资源描述：
《硅超大规模集成电路工艺技术―理论、实践与模型_课后习题答案.doc》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、1.2.Assumingdopantatomsareuniformlydistributedinasiliconcrystal,howfarapartaretheseatomswhenthedopingconcentrationisa).1015cm-3,b).1018cm-3,c).5x1020cm-3. Answer: Theaveragedistancebetweenthedopantatomswouldjustbeoneoverthecuberootofthedopantconcentration: a)b)c) 1.3.Considerap
2、ieceofpuresilicon100µmlongwithacross-sectionalareaof1µm2.Howmuchcurrentwouldflowthroughthis“resistor”atroomtemperatureinresponsetoanappliedvoltageof1volt? Answer: Ifthesiliconispure,thenthecarrierconcentrationwillbesimplyni.Atroomtemperature,ni≈1.45x1010cm-3.Underanappliedfield
3、,thecurrentwillbeduetodriftandhence, 1.10.Astate-of-the-artNMOStransistormighthaveadrainjunctionareaof0.5x0.5µm.Calculatethejunctioncapacitanceassociatedwiththisjunctionatanappliedreversebiasof2volts.Assumethedrainregionisveryheavilydopedandthesubstratedopingis1x1016cm-3. Answe
4、r: ThecapacitanceofthejunctionisgivenbyEqn.1.25. Thejunctionbuilt-involtageisgivenbyEqn.1.24.NDisnotspecifiedexceptthatitisverylarge,sowetakeittobe1020cm-3(roughlysolidsolubility).TheexactchoiceforNDdoesn'tmakemuchdifferenceintheanswer. SinceND>>NAinthisstructure,thecapacitan
5、ceexpressionsimplifiesto Giventheareaofthejunction(0.25x10-8cm2,thejunctioncapacitanceisthus4.2x10-17Farads. 3.2.Aboron-dopedcrystalpulledbytheCzochralskitechniqueisrequiredtohavearesistivityof10Ωcmwhenhalfthecrystalisgrown.Assumingthata100gmpuresiliconchargeisused,howmuch0.0
6、1Ωcmborondopedsiliconmustbeaddedtothemelt?Forthiscrystal,plotresistivityasafunctionofthefractionofthemeltsolidified.Assumek0=0.8andtheholemobilityµp=550cm2volt-1sec-1. Answer:Usingthemobilityvaluegiven,andwehave: 10ΩcmÞNA=1.14x1015cm-3and0.01ΩcmÞNA=1.14x1018cm-3 FromEqn.3.38,an
7、dwewantCS=1.14x1015cm-3whenf=0.5.Thus,solvingforC0theinitialdopingconcentrationinthemelt,wehave: Theresistivityasafunctionofdistanceisplottedbelowandisgivenby 3.3.ACzochralskicrystalispulledfromameltcontaining1015cm-3boronand2x1014cm-3phosphorus.InitiallythecrystalwillbePty
8、pebutasitispulled,moreandmorephosphoruswillbuildupinth
