▁temper atures ▁raise ▁the ▁thermal ▁budget ▁and ▁costs . ▁Additionally , ▁co ev ap oration ▁is ▁pl ag ued ▁by ▁low ▁material ▁util ization ▁( de position ▁on ▁chamber ▁walls ▁instead ▁of ▁the ▁substr ate , ▁especially ▁for ▁selenium ) ▁and ▁expensive ▁vac u um ▁equipment . ▁A ▁way ▁to ▁enh ance ▁Se ▁util isation ▁is ▁via ▁a ▁thermal ▁or ▁pl asma - en hanced ▁selenium - c rack ing ▁process , ▁which ▁can ▁be ▁couple d ▁with ▁an ▁ion ▁beam ▁source ▁for ▁ion ▁beam ▁assist ed ▁de position . ▁ ▁Chem ical ▁v apor ▁de position ▁▁ ▁Chem ical ▁v apor ▁de position ▁( C VD ) ▁has ▁been ▁implemented ▁in ▁multiple ▁ways ▁for ▁the ▁de position ▁of ▁C IG S . ▁Process es ▁include ▁atmosphere ▁pressure ▁metal ▁organ ic ▁C VD ▁( AP - MO C VD ), ▁pl asma - en hanced ▁C VD ▁( PE C VD ), ▁low - press ure ▁MO C VD ▁( LP - MO C VD ), ▁and ▁a eros ol ▁assist ed ▁MO C VD ▁( AA - MO C VD ). ▁Research ▁is ▁attempting ▁to ▁switch ▁from ▁dual - source ▁prec urs ors ▁to ▁single - source ▁prec urs ors . ▁Multiple ▁source ▁prec urs ors ▁must ▁be ▁hom ogene ously ▁mixed ▁and ▁the ▁flow ▁rates ▁of ▁the ▁prec urs ors ▁have ▁to ▁be ▁kept ▁at ▁the ▁proper ▁sto ichi ometry . ▁Single - source ▁prec ursor ▁methods ▁do ▁not ▁suffer ▁from ▁these ▁draw back s ▁and ▁should ▁enable ▁better ▁control ▁of