Influence of substrate temperature and thermal treatment on sputtered ZnO:B using B2H6 as doping source

摘要

In the present study,boron doped zinc oxide (ZnO:B) films deposited by RF magnetron sputtering using an undoped ZnO ceramic target were prepared.Diborane (B2H6) was introduced into sputtering atmosphere as doping source.Substrate temperature was varied from 50 to 200 oC in order to adjust crystalline quality.The resistivity increased from 1.5×10.3Ωcm to 8.4×10.3Ωcm as temperature rising above 70℃.Carrier concentration dropped from 2.3×1020cm.3 to 7.8×1019cm.3 while mobility dropped from 18.9cm2/Vs to 7.1cm2/Vs.This indicated that the substrate temperature plays an important role on the doping efficiency of B2H6 in gas source magnetron sputtering growth of conductive ZnO:B films.Under the optimal deposition temperature (about 70 ℃ in our system),ZnO:B film with low resistivity (1.5х10-3 Ωcm) and high transparency (average transparency from 400 nm to 1300 nm was over 87％) was obtained.After thermal treatment,the resistivity decreased to 8.6 ×10.4Ω·cm,with mobility increased to 28.4 cm2/Vs.