Fabrication of micro-tips with self-developed auto-detecting micro-tip maker and their multiple applications

Chia Chun Wei^1*, Cheng Yu Wu¹, Che Chi Shih¹, Wen Pin Chien¹

¹Department of electrophysics, National Chiao Tung University, Hisnchu, Taiwan

* Presenter:Chia Chun Wei, email:geneadsl@gmail.com

With the progress of technology, the semiconductor industry have made the dimension of their device become smaller and smaller in order to get better performance and have more efficient power consumption. Accompany with this procedure, it is also very important to keep working on the relating technique such as Scanning Probe Microscopy (SPM) technique and measurement system.
In this work, we started from constructing an auto-detecting micro-tip maker that has the capability of having a good control of the electronic condition to form tips. Excluding the electronic condition, this study can also control the shape of tips precisely by adjusting several parameters like immersion depth of wire, wire diameter and concentration of etching solution. After forming the tips, we executed statistical analysis on tips by taking the cone angle, apex circle radius and tapered cone length into consideration.
Until now, we developed four different fabrication modes for making micro-tips: AC Etching Mode, DC Etching Mode, AC-DC Etching Mode and AC-DC Pull-up Etching Mode separately. By choosing different mode, we can get varying types of tip that is suitable in a number of applications.
In future work, we are going to produce Au-tip by reforming the present auto-detecting tip maker. Next, utilizing this Au-tip on our self-developed Scanning Tunneling Microscope (STM) to make sure that we can obtain high-quality scanning result comparing to traditional Tungsten-tips. Furthermore, we will combine our STM system with Raman Spectrometer for the purpose of performing Tip-enhanced Raman Spectroscopy (TERS), which is an avant-garde technology in study molecular with topographic and chemical information.

Keywords: Micro-tip, STM, electroetching, TERS