Boron-Doped Plasma Enhanced Chemical Vapor Deposition of ZnO Thin Films

Highly conducting boron-doped ZnO thin films have been grown at low temperature ( 200 ° C ) by plasma enhanced chemical vapor deposition using diethyl zinc [ Zn ( C 2 H 5 ) 2 ] , carbon dioxide ( CO 2 ) , triethylboron, and argon gas mixtures. The minimum resistivity is < 4 × 10 − 4 Ω cm with an excellent optical transmission ( 85 % for the visible spectrum). The free-electron concentration, determined by Hall effect measurement, was as high as 1 × 10 21 / cm 3 with a mobility of 13.5 cm 2 / V s . For this deposition approach, the low-reactivity oxidant CO 2 allows a uniform film growth over a large area, and the low-toxicity triethylboron allows a simple and convenient boron doping.