GaN-HEMT器件

DetectionofchlorideionsusinganintegratedAg∕AgClelectrodewithAlGaN∕GaNhighelectronmobilitytransistorsS.C.Hung,Y.L.Wang,B.Hicks,S.J.Pearton,D.M.Dennis,F.Ren,J.W.Johnson,P.Rajagopal,J.C.Roberts,E.L.Piner,K.J.Linthicum,andG.C.ChiCitation:AppliedPhysicsLetters92,193903(2008);doi:10.1063/1.2927372Viewonline::=pdfcovPublishedbytheAIPPublishingArticlesyoumaybeinterestedinEffectsofprotonirradiationenergiesondegradationofAlGaN/GaNhighelectronmobilitytransistorsJ.Vac.Sci.Technol.B30,012202(2012);10.1116/1.3676034ChlorideiondetectionbyInNgatedAlGaN∕GaNhighelectronmobilitytransistorsJ.Vac.Sci.Technol.B28,L5(2010);10.1116/1.3271253pHsensorusingAlGaN∕GaNhighelectronmobilitytransistorswithSc2O3inthegateregionAppl.Phys.Lett.91,012110(2007);10.1063/1.2754637DetectionofhalideionswithAlGaN∕GaNhighelectronmobilitytransistorsAppl.Phys.Lett.86,173502(2005);10.1063/1.1920433SurfacephotovoltagespectroscopyofmetamorphichighelectronmobilitytransistorstructuresJ.Vac.Sci.Technol.B22,2434(2004);10.1116/1.1787518ReuseofAIPPublishingcontentissubjecttothetermsat::113.240.234.253On:Sat,02Jul201602:42:54DetectionofchlorideionsusinganintegratedAg/AgClelectrodewithAlGaN/GaNhighelectronmobilitytransistorsS.C.Hung,1,2Y.L.Wang,1B.Hicks,3S.J.Pearton,1D.M.Dennis,4F.Ren,3,a
J.W.Johnson,5P.Rajagopal,5J.C.Roberts,5E.L.Piner,5K.J.Linthicum,5andG.C.Chi21DepartmentofMaterialScienceandEngineering,UniversityofFlorida,Florida32611,USA2DepartmentofPhysics,NationalCentralUniversity,Jhong-Li320,Taiwan3DepartmentofChemicalEngineering,UniversityofFlorida,Gainesville,Florida32611,USA4DepartmentofAnesthesiology,UniversityofFlorida,Gainesville,Florida32611,USA5NitronexCorporation,Durham,NorthCarolina27703,USA
Received17March2008;accepted9April2008;publishedonline14May2008AlGaN/GaNhighelectronmobilitytransistors
HEMTswithanAg/AgClgateexhibitsignificantchangesinchannelconductanceuponexposingthegateregiontovariousconcentrationsofchloride
Cl−ion.TheAg/AgClgateelectrode,preparedbypotentiostaticanodization,changeselectricalpotentialwhenitencountersCl−ions.ThisgatepotentialchangesleadtoachangeofsurfacechargeinthegateregionoftheHEMT,inducingahigherpositivechargeontheAlGaNsurface,andincreasingthepiezoinducedchargedensityintheHEMTchannel.TheseanionscreateanimagepositivechargeontheAggatemetalfortherequiredneutrality,thusincreasingthedraincurrentoftheHEMT.TheHEMTsource-draincurrentwashighlydependentonCl−ionconcentration.Thelimitofdetectionachievedwas1
10−8Musinga20
50m2gatesensingarea.©2008AmericanInstituteofPhysics.DOI:10.1063/1.2927372Chlorineiswidelyusedinthemanufactureofmanyproductsanditemsdirectlyorindirectly,i.e.,inpaperprod-uctproduction,antiseptic,dyestuffs,food,insecticides,paints,petroleumproducts,plastics,medicines,textiles,sol-vents,andmanyotherconsumerproducts.Itisusedtokillbacteriaandothermicrobesindrinkingwatersuppliesandwastewatertreatment.Excesschlorinealsoreactswithor-ganicsandformsdisinfectionby-productssuchascarcino-genicchloroform,whichisharmfultohumanhealth.Thus,toensurethesafetyofpublichealth,itisveryimportanttoaccuratelyandeffectivelymonitorchlorineresidues,includ-ingthoseintheformofCl−ions,duringthetreatmentandtransportofdrinkingwater.1,2Althoughthetreatmentofwa-terwithchlorinefordisinfectiontypicallyleadstothefor-mationofhypochloriteions,thechloridecontentinwatermayalsobeconsiderablyincreased.TheCl−ionisanessentialmineralforhumans.Thetotalbodybalanceofchloride,particularlytheplasmalevelsofthismonovalentanion,iscarefullyregulatedbythekidneys.Chlorideisfoundinmost,ifnotall,bodyfluids,includingblood,plasma,serum,urine,saliva,andexhaledbreathcon-densate.Thenormalbloodconcentrationofchlorideinadultsisapproximately95–105mequivalent/l.Variationsinthechlorideconcentrationinbloodmayindicatethepres-enceofanumberofimportantdiseasessuchasrenaldys-function,metabolicdisturbances,adrenalism,andpneumo-nia.Therefore,themeasurementofthisparameterisclinicallyimportant.3Severalanalyticalmethodssuchascolorimetry,4ion-selectiveelectrode,5activationanalysis,6x-rayfluorescencespectrometry,7andionchromatography8,9havebeenusedfortheanalysisofchlorideinvarioussamples.However,thesemethodsarenotportableandre-quireexpensiveinstrumentation.Anaccurateandfastdeter-minationoftheinorganicioncontentofvariousaqueoussamplesatlowdetectionlimitshasbeenofgreatinterestforalongtime.Recently,AlGaN/GaNhighelectronmobilitytransistors
HEMTshaveshownpromiseforsuchapplications.10–19Thisisduetotheirhighelectronsheetcarrierconcentrationchannelinducedbybothpiezoelectricpolarizationandspon-taneouspolarization.20,21Unlikeconventionalsemiconductorfieldeffecttransistors,thereisnointentionaldopantintheAlGaN/GaNHEMTstructure.Theelectronsinthetwo-dimensionalelectrongas
2DEGchannelarelocatedattheinterfacebetweentheAlGaNlayerandGaNlayerandtherearepositivecounterchargesattheHEMTsurfacelayerin-ducedbythe2DEG.Slightchangesintheambi