Low-current Scanning Tunneling Microscope for Nanoscale Imaging

Defence Science Journal

R.K. Kale¹ 

[1] Defence Institute of Advanced Technology, Pune

关键词: Nanoscale imaging;    low-current STM;    nanotechnology;    scanning tunneling microscopy;    scanning probe microscopy;   

DOI  :  

学科分类：社会科学、人文和艺术（综合）

来源: Defence Scientific Information & Documentation Centre

【 摘 要 】

Advances in the nanotechnology, which is still in its infancy, will depend on our ability to design, build, replicate, and mass-produce usable nanoscale systems. At sub-nanometer length scales, scanning tunneling microscopy (STM) and the related techniques, collectively called scanning probe microscopies, replace the optical microscopy for real-space imaging and manipulation of materials. STM operation is based on measurement of current due to tunneling of electrons across a finite potential barrier between the probe and the sample. In conventional STM, tunneling current of tens of nA and probe-sample distance of a few Å are maintained. These conditions, while necessary for atomic-scale imaging under ultra high vacuum environment, are not suited to handle nanostructures. Quantum structures deposited on a flat substrate usually present a non-metallic sample, and the roughness levels involved are much too high for conventional STM. STM operation with low tunneling current (few pA) and larger tunneling gap (several nm) is preferred to overcome these difficulties. This paper presents experimental work and theoretical considerations for developing an atmospheric low-current STM (LC-STM). Researchers from diverse fields can build their own LC-STM for routine imaging and spectroscopy. Several design details are included keeping this aspect in mind.

【 授权许可】

Unknown