6.152J3.155J CRYSTAL GROWITH 6.12J/3.155J Microelectronic pn CRYSTAL GROWTH step Crystal and questlons 1. Reactants In molten form 2. Transport to s/L Interface TAS Increases AH decreases 4 CHtcal nucleus slze 6. Impurities, defects more stable at high T how grow pure crystal 7. Segregation solld vS. quid What do we need to know pror to crystal growth? N。v.26,2003 Defects and crystal growth 6.12J/3. 155J Microelectronic processing e Defects impurities, vacancies, dislocations .. T dependence e Crystal growth techniques: float zone, Bridgman, Czochralski Segregation during growth Segregation coefficients Nov.26,20036.152J/3.155J 1 1 Nov.26 , 2003 6.12J / 3.155J Microelectronic processing CRYSTAL GROWTH Si Crystal What do we need to know prior to crystal growth? 4. Critical nucleus size 5. Growth 6. Impurities, defects more stable at high T ; how grow pure crystal? 7. Segregation solid vs. liquid 1. Reactants in molten form 2. Transport to S/L interface 3. Adsorbtion: entropy decreases CRYSTAL GROWTH steps and questions DS DH -TDS increases DH decreases (exo) 2 Nov.26 , 2003 6.12J / 3.155J Microelectronic processing Defects and crystal growth •Defects impurities, vacancies, dislocations…T dependence •Crystal growth techniques: float zone, Bridgman, Czochralski •Segregation during growth Segregation coefficients