Infrared conductivity mapping for nanoelectronics

With ever shrinking dimensions in microelectronics, the conductivity performance of charge carriers approaches physical limits and demands tighter control. We show that near-field microscopy carried out at sufficiently long infrared wavelengths-below the plasma frequency-selectively detects and characterizes subsurface mobile carriers with 30 nm resolution, timely for next generation chips as well as for fundamental research, e.g., on low-dimensional electron systems. (C) 2000 American Institute of Physics. [S0003-6951(00)00850-0].