Scanning spreading resistance microscopy study of a metalorganic chemical vapor deposited grown InP optoelectronic structure

Scanning spreading resistance microscopy (SSRM) is a promising new tool for dopant profiling in semiconductor materials. We present the results of a SSRM study of the cross section of a metalorganic chemical vapor deposited grown optoelectronic structure. The SSRM measurements are compared with the secondary ion mass spectrometry (SIMS) and excellent spatial agreement is obtained. However, we find that obtaining quantitative agreement with SIMS is complicated by the differing nonlinear I-V characteristics of n- and p-type InP. The results suggest that obtaining quantitative agreement with SIMS would require calibration of each SSRM probe tip with both n- and p-type materials. The high spatial resolution of the technique is demonstrated by our ability to easily resolve the 17.5 nm quantum well and barrier layer structure of the device. The results suggest that the greatest strength of SSRM will be the delineation of complex buried semiconductor structures.