Reproducible growth of p-type ZnO:N using a modified atomic layer deposition process combined with dark annealing

Nitrogen doped ZnO (ZnO:N) films were deposited by atmospheric atomic layer deposition (ALD) between 100 and 300 degrees C. Postannealing was required to remove compensating defects. After a low temperature dark annealing, originally n-type films became p-type. Films deposited at low temperatures (<= 150 degrees C) have low hole mobilities (mu) of 0.2-0.4 cm(2) V-1 s(-1) and moderate hole concentrations (n(p)) of around 1 x 10(15) cm(-3). Higher temperature deposited films (>= 200 degrees C) have higher mu values (6 cm(2) V-1 s(-1)) but n(p) values <1 x 10(13) cm(-3). This crossover in transport properties can be explained by the opposing effects of deposition temperature on nitrogen doping level and distribution, and film crystallinity. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3000604]