STM/STS study of SI nano pn junctions under Illumination

摘要

Silicon pn junctions are widely used as the fundamental structures of semiconductor devices. They are also very important both in modern electornic applications and in understanding semiconductor devices. As those devices are getting smaller and smaller in size, it is required to characterize their structures and local electronic properties on a nano scale. We have already visualized and characterized nano pn junctions fabricated by ion implantation on Si(001) surfaces with the use of scanning tunneling microscopy/scanning tunneling spectroscopy (STM/STS) [1,2]. It is possible to distinguish p-type, depleted p-type, and n~+-type regions both from STM topographic images and from tunneling current-bias voltage (I-V) curves. In this paper, we focus on the visualization of electrical properties in Si nano pn junctions in operation, especially under illumination.