Access to residual carrier concentration in ZnO nanowires by calibrated scanning spreading resistance microscopy

作者：Wang L^*; Chauveau M; Brenier R; Sallet V; Jomard F; Sartel C; Bremond G

来源：Applied Physics Letters, 2016, 108(13): 132103.

DOI：10.1063/1.4945100

Scanning spreading resistance microscopy (SSRM) was performed on non-intentionally doped (nid) ZnO nanowires (NWs) grown by metal-organic chemical vapor deposition in order to measure their residual carrier concentration. For this purpose, an SSRM calibration profile has been developed on homoepitaxial ZnO:Ga multilayer staircase structures grown by molecular beam epitaxy. The Ga density measured by SIMS varies in the 1.7 x 10 17 cm(-3) to 3 x 10(20) cm(-3) range. From measurements on such Ga doped multi-layers, a monotonic decrease in SSRM resistance with increasing Ga density was established, indicating SSRM being a well-adapted technique for two dimensional dopant/carrier profiling on ZnO at nanoscale. Finally, relevant SSRM signal contrasts were detected on nid ZnO NWs, and the residual carrier concentration is estimated in the 1-3 x 10(18) cm(-3) range, in agreement with the result from four-probe measurements.

• 出版日期2016-3-28