Highly conductive thin films of ZnO doped with Ga were grown by pulsed-laser deposition (PLD) with 10 mTorr of H2 in the growth chamber. Compared with a more conventional method of producing conductive films of ZnO, i.e., growth in O2 followed by annealing in forming gas (5% H2 in Ar), the H2 method requires no post-growth anneal and also produces higher carrier concentrations and lower resistivities with better depth uniformity. As an example, a 65-nm-thick sample had a room-temperature mobility of 32 cm2/V-s, a concentration of 6.8 x 1020 cm-3, and a resistivity of 2.9 x 10^-4 ohm-cm. From a scattering model, the donor and acceptor concentrations were calculated as 8.9 x 1020 and 2.1 x 10^20 cm-3, respectively, as compared to the Ga and H concentrations of 11 x 10^20 and 1 x 10^20 cm-3. Thus, H does not play a significant role as a donor in this type of ZnO
Revised: August 18, 2014 |
Published: January 11, 2011
Citation
Look D., T.C. Droubay, J.S. McCloy, Z. Zhu, and S.A. Chambers. 2011.Ga-doped ZnO grown by pulsed laser deposition in H2: the roles of Ga and H.Journal of Vacuum Science and Technology A--Vacuum, Surfaces and Films 29, no. 3:Article No.: 03A102.PNNL-SA-74572.doi:10.1116/1.3523296