Microelectronicsver. 1ME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 20091Microelectronics - Overview• Silicon Manufacture• Photolithography• Deposition Techniques• OxidationME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 20092Microelectronics – Then and Now~ 1 cmWilliam Shockley, John Bardeen, Walter Brattain and at BellModern Intel Pentium 4 – approx.140 million transistorsME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 20093Walter Brattain, and at Bell Laboratories, “First Transistor” 1947140 million transistorsFirst orking ICFirst working ICJack Kilby, TI 1958First planar transistorJean Hoerni, Fairchild, 1959ME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 20094First commercial ICRobert Royce, Fairchild, 1961ME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 20095Robert Royce, Fairchild, 1961Intel 8080, 19745 000 transistors5,000 transistorsIntel 8086, 197829,000 transistorsIntel 386, 1985275 000 transistors275,000 transistorsAMD 386, 1991200,000 transistorsME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 20096Motorola 68000, 1979Motorola 68000, 197968,000 transistorsME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 20097Intel Pentium, 19933.1 MM transistorsIBM PowerPC 601, 19932.8 MM transistorsME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 20098Intel Pentium 4, 200042 MM transistorsIntel Core 2 Duo, 2007ME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2009942 MM transistorsIntel Core 2 Duo, 2007410 MM transistorsIntel Core i7, 2008731 MM transistorsAMD Phenom II, 2009758 MM transistorsME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200910758 MM transistorsMicroelectronics - PackagingSilicon circuit packaged for protectionDie connected to package via wirebondingME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200911MOS Transistor FabricationME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200912Microelectronics – Integrated CircuitME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200913Process FlowWafersDevicesDepositionLithographyEtchDepositionLithographyEtchME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200914Silicon Wafer Production - Czochralski• Czochralski (CZ) method • Boule pulled from molten silicon1” to 12” diameter•1” to 12” diameter• 1500 C• 1-3 cm/hrME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200915Silicon Wafer Production – Float Zone• Float Zone (FZ) Mhdb iMethod begins with polycrystalline rod•RF heating coil•RF heating coil scanned along rod• Melted region recrystallizes into ysingle-crystal– impurities “swept”to end of rodlti l–multiple passes used to make crystal “pure”ME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200916Wafer SlicingSilicon Boules Wire cuttingWafer cuttingME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200917Chemical-Mechanical Polishing (CMP)PadSlurryHolderWaferTablePadTableME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200918Chemical-Mechanical PolishingCMP MachineRough wafers prior to polishingME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200919Process FlowWafers DevicesDeposition Lithography EtchPhoto resist coatingPattern transferPhoto resist removalME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200920Photolithography – Pattern Transfer• Lithography (Greek, “stone-writing”)stonewriting)• Pattern Transfer–Application of photosensitive photoresist–Optical exposure toOptical exposure to transfer image from mask to photoresist– Resist can be negative or positiveor positive– Width of line limited by wavelength of “light”ME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200921Photolithography – Photoresist Deposition• Photoresist typically photosensitive viscousdispenserhiphotosensitive viscous polymer• Spin coated onto waferac m ch ckphotoresistwafer• Viscosity and rpm determine thickness• 3000 – 6000 rpm, vacuum chuck15-30 sec• Soft bake ->alignment ->exposureωspinlevel out>exposuretslowcoatpdownME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200922tPhotolithography - EquipmentMask –reflective chrome on transparent glassKlS MJB3 kliME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200923Karl Suss MJB3 mask alignerPhotolithography – Complex Pattern TfTransfercircuit patternwaferME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200924Process FlowWafers DevicesDeposition LithographyEtchSputteringEvaporationOxidationCVDSol-gelEpitaxyME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200925Deposition - Sputtering•Sputtered metals and dielectrics•Argon ions bombards targetArgon ions bombards target•Ejected material takes ballistic path to wafers•Typically line-of-sight from a distributed source•Requires high vacuum but lowRequires high vacuum, but low temperatureME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200926Sputtering SystemDeposition - Evaporation• Evaporated metals in a tungsten crucible– Aluminum, gold, Pt, W• Evaporated metals and dielectrics by electron-beam or resistance heatingresistance heating• Typically line-of-sight deposition• Very high-vacuum required to prevent oxidation load lockE-beam evaporator - schematicprevent oxidation, load lockME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 200927E-beam evaporator (GaTech MiRC)Deposition - Chemical Vapor Deposition (CVD)• Thermal energy to dissociate gases and deposit thin films on surfaces, high productivity, better step coveragepy, pg• low pressure (LPCVD), atmospheric pressure (APCVD), plasma enhanced (PECVD), horizontal, vertical•LPCVD pressures around 300mT (0.05% p(atmosphere)• Moderate Temperatures– 450oC SiO2 : PSG, LTO580650oC polysilicon–580-650oC polysilicon– 800oC SixNy– SiH4+ NH3• Very dangerous gases–Silane: SiH44– Arsine, phosphine, diborane: AsH3, PH3, B2H6ME 4210: Manufacturing Processes and Engineering Prof.