Abstract
Microcharacterization of semiconductor devices is performed using scanning tunneling microscopy (STM). Novel impurity profiling method employing chemical etching and STM measurements is proposed. This method reveals localization of Zn segregation at the heterointerface of n-InP/InGaAsp and enables profiling a wide range of boron impurity concentration (1016_??_1020cm-3) with spatial resolution of 10nm. Spectroscopic technique is successfully applied to identify each layer of double heterostructure for laser diodes. This technique also clarified that spectra for ultra-thin (1.5nm) SiO2 on Si structure reflect the band structure of Si substrate together with SiO2/Si interface gap-states and spectra on depressed sites of STM images show negative differential resistance associated with oxide defects. Fowler-Nordheim tunneling characteristics is also found for the relatively thick (2.5nm) SiO2/Si structures.
