Abstract Virtually complete charge transfer can be achieved with charge coupleddevices(CCDs)intheburiedchannelconfigurationbecausetheburiedchannelCCDintroduces no transfer noise. However, conventional charge detectors incorporatedinto CCDs have a comparably large noise, which consists of thermal noise and 1/fnoisefromMOS transistorin theoutputchargedetectors.
Chapter10
Low-NoiseElectronicImaging
withDouble-GateFETs
andCharge-ModulationDevices
YoshiyukiMatsunaga
AbstractVirtuallycompletechargetransfercanbeachievedwithchargecoupleddevices(CCDs)intheburiedchannelcon gurationbecausetheburiedchannelCCDintroducesnotransfernoise.However,conventionalchargedetectorsincorporatedintoCCDshaveacomparablylargenoise,whichconsistsofthermalnoiseand1/fnoisefromMOStransistorintheoutputchargedetectors.
HighlysensitivedoublegatechargedetectorsarepresentedinthischaptertoshowtheabilityofCCDlownoiseperformanceoflessthan1electronrmsatroomtemperatureandatvideofrequency.
Theconceptofdoublegatechargedetectioncanalternativelybeimplementedinapixelincorporatingachargemodulationdevice(CMD),reachingalsoaneffectivereadoutnoiseleveloflessthan1electronrms.Inpractice,theCMDshowslarger xed-patternnoisebehavior,necessitatingsupplementarysignalprocessingefforts.10.1Introduction
Chargecoupleddevices(CCDs)haveachievedvirtuallycompletechargetransferbyusingtheburied-channelcon guration,resultinginchargetransferinef cienciesoflessthan10 6.Also,theburied-channelCCDoperationintroducesnotransfernoise.However,conventionalchargedetectioncircuitsemployedinCCDshaveacomparativelylargenoise,whichconsistsofthermalnoiseand1=fnoisefrommetaloxidesemiconductor(MOS)transistorsinthechargedetectors[1].ThedetectornoisesourcesdegradetheCCDperformancesigni cantly.
Inthischapter,highlysensitivedouble-gatechargedetectordevicesarepresentedtoexploittheabilityofCCDlownoiseperformancewhichisoneofthemostimpor-tantcharacteristicsforimagesensorapplications.LowleakagecurrentCCDsensorswithalow-noisechargedetectorwillideallybealmostnoiselessphotosensorsInaddition,anewcharge-modulationimagepixelispresentedforapplicationsofthedouble-gatedetectors.
P.SeitzandA.J.P.Theuwissen(eds.),Single-PhotonImaging,
SpringerSeriesinOpticalSciences160,DOI10.1007/978-3-642-18443-7©Springer-VerlagBerlinHeidelberg2011219
