An investigation of electrical and structural properties of Ni-germanosilicided Schottky diode q A.R.Saha a, * ,S.Chattopadhyay a,b ,G.K.Dalapati a ,S.K.Nandi a ,C.K.Maiti a a Department of Electronics & ECE, IIT Kharagpur 721 302, India b School of Electrical, Electronic and Computer Engineering, University of Newcastle, Newcastle upon Tyne, NE1 7RU, UK Received 1 July 2004; received in revised form 2 August 2004 Abstract Ni-germanosilicided Schottky barrier diode has been fabricated by annealing the deposited Ni film on strained-Si and characterized electrically in the temperature range of 125K–300K. The chemical phases and morphology of the germanosilicidedfilmswerestudiedbyusingscanningelectronmicroscopy(SEM),cross-sectionaltransmissionelectron microscopy(TEM)andenergydispersivespectroscopy(EDS).TheSchottkybarrierheight(/ b ),idealityfactor(n)and interfacestatedensity(D it )havebeendeterminedfromthecurrent–voltage(I–V)andcapacitance–voltage(C–V)char- acteristics.Thecurrent–voltagecharacteristicshavealsobeensimulatedusingSEMICADdevicesimulatortomodelthe Schottkyjunction.Aninterfaciallayerandaseriesresistancewereincludedinthediodemodeltoachieveabetteragree- mentwiththeexperimentaldata.Ithasbeenfoundthatthebarrierheightvaluesextractedfromthe I–V and C–V char- acteristics are different, indicating the existence of an in-homogeneous Schottky interface. Results are also compared with bulk-Si Schottky diode processed in the same run. The variation of electrical properties between the strained- and bulk-Si Schottky diodes has been attributed to the presence of out-diffused Ge at the interface. Ó 2004 Elsevier Ltd. All rights reserved. 1. Introduction During last two decades, the advancement of Si 1x - Ge x strained layers has attracted much attention for novel band-gap engineered heterostructure devices with significantly improved performance compared to their bulk-Si counterpart. Several authors [1,2] have studied carrier transport in both strained-Si 1x Ge x and strained-Si and superior carrier transport properties have been reported for strained-Si when compared to thatofbulk-Si.Asboththeelectronandholemobilities are high, strained-Si on relaxed Si 1x Ge x virtual sub- strate (VS) may find potential applications in high performance heterostructure field effect transistors (HFETs) and heterostructure complementary metal oxide semiconductor (HCMOS) devices. All these de- vicesrequireagoodandreliablecontactfortheirsuccess- ful operation. In CMOS technologies, several metals suchasTi,Co,Pt,Pd,andNihavebeenusedascontact materialsastheirsilicidesarethermallystableandcom- patible with the existing process technology. But a low temperature silicide growth is desirable for the strained-Si 1x Ge x material systems so that their strain is retained after processing. Nickel-monosilicides (NiSi) 0026-2714/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.microrel.2004.08.012 q An earlier version of this paper was published in the Proceedings of 24th International Conference on Microelec- tronics(MIEL2004),16–19May,Nis,SerbiaandMontenegro 2004, vol.1, pp.401–404. * Corresponding author. Fax: +91 3222 255303. E-mail address: arup025@yahoo.co.in (A.R. Saha). Microelectronics Reliability 45 (2005) 1154–1160 www.elsevier.com/locate/microrel