Complete Report - University of New South Wales

ARCPHOTOVOLTAICSCENTRE OFEXCELLENCE2010/11ANNUAL REPORTBay Street Clean Room Sputter Machine.Figure 4.2.10UHV Electron Beam Evaporator.Figure 4.2.11Thin-Film Clean Room facility inBay Street, BotanyIn 2003, the Centre added a 120 m 2 cleanroomfacility in Bay Street, Botany to its infrastructure,greatly improving its experimental capabilities inthe area of thin-films. This cleanroom is equippedwith several fume cupboards, two tube furnaces,an electron-beam vacuum evaporator, a thermalvacuum evaporator, a glass washing machine, arapid thermal processing (RTP) machine and a5-chamber cluster tool. The cluster tool presentlyfeatures four plasma-enhanced chemical vapourdeposition (PECVD) chambers and one lampheatedvacuum annealing chamber. The PECVDchambers enable the low-temperature depositionof dielectric films (silicon oxide, silicon nitride,etc) and amorphous silicon films (either n- orp-doped or undoped). Furthermore, samplescan be hydrogenated by PECVD using hydrogenplasma at substrate temperatures of up to 480°C.During 2004, the Centre purchased a low-pressurechemical vapour deposition (LPCVD) system, aninfrared NdYAG laser scriber and a box furnace forsample annealing. The LPCVD system is capable ofdepositing doped crystalline silicon on glass andwith its additional remote plasma source is currentlyengaged in hydrogenation work. The NdYAGlaser, located outside the clean room, is used forscribing silicon films and other suitable metal anddielectric materials.In 2006, a state of the art multi-target sputtermachine was installed. In 2008 this vacuum toolwas upgraded from four to five separate targets.Each target is able to be operated independentlyof one and other, allowing users to cosputter athin film from more than one target and depositmultilayers without breaking vacuum. Three powersupplies are available with substrate biasing. Thecustom made system can handle substrates up to150mm x 150mm. Excellent film purity is assuredas the system incorporates a load-lock. Computercontrol can be used for most operations, includingsubstrate heating, allowing precise multilayers to bedeposited repeatedly.In 2009, an optically assisted IV measurementsystem was installed for the determination of statichot carrier distributions. The LPCVD computercontrol system was also upgraded to provideenhanced throughput. A line beam diode lasersystem was also installed, outside the clean room,for work on low thermal budget defect annealing.In 2010, the first stage of a multi-chambersputter system has been ordered to allow our 3 rdGeneration Group to carry out significantly differentfunctions on a sample without exposing it to theatmosphere between each process. Processesinclude sputter-depositing different dopants inseparate chambers, vacuum annealing, also PECVDlayers. This purchase will be “Stage I” in that onechamber will be purchased; a loadlock chamberand other peripherals have been configured fromdecommissioned stock. Stage II will involve thepurchase of a second processing chamber and atransfer/loadlock chamber.The addition of computer control to ourhydrogenation tool provides more reliableprocess repeatability and accuracy of set processparameters. The processor inputs all processparameters for each “layer” defining each stepbefore starting the process. This upgrade alsofrees processors’ time in that they need not be inattendance to change settings when beginningeach process layer.Organic Photovoltaic Laboratory (OPV)In 2010 fit out of a new OPV laboratory in theChemical Sciences Building commenced andOPV equipment currently located in other Centrelaboratories is being integrated into the new facility.A recent arrival has been the inert atmosphere, fourglove boxes with integrated spin coater. The newlaboratory includes the Centre’s first fume cupboardwith integral hydrofluoric acid scrubber as well assupport space for vacuum evaporation, annealingand sample storage.During 2007, a new computer controlled multipocket, multi source UHV electron beam evaporatorsystem was delivered. This equipment provides thecapability for high “industrial” rate silicon and otherthin film deposition.20