A special scanning capacitance microscopy (SCM) sample preparation method is exploited to make unipolar and p-n junction samples with different interface state densities and an identical oxide thickness. Using these samples, the interface states effect on SCM measurements is singled out. SCM measurements on those junction samples are performed with and without the atomic force microscopy laser illumination. Results show both the interface charges and the illumination significantly affect the SCM signals of p-n junctions. Qualitative SCM p-n junction dopant profiling can be achieved by avoiding or correctly modeling these two factors in the experiment and the simulation.
Citation: Microelectronics Reliability
Pub Type: Journals
dopant profiling, interface face traps, scanning capacitance microscopy, SCM