PC-CONTROLLED
SCANNING TUNNELING MICROSCOPE

ECE 476 SPRING 2002 FINAL PROJECT

 
INTRODUCTION
 
 
For our final project, we designed a scanning tunneling microscope (STM) that could be used to gather information about the surface topography of metals and semiconductors at the sub-micron scale. The STM is controlled from a graphical user interface running on a PC. The user is able to set various parameters related to the operation of the device such as scan area, sample bias, sample-tip separation and the number of averages per data point (if averaging is turned on). The output of the scanning operation is a data file listing the sample-tip separation at each x-y location. This file can be opened/plotted with various programs (Matlab, Excel etc.) to examine the results. Also, a simple topological image is created on the GUI panel and can be viewed in real-time as the data is taken.
 
The main motivation behind our project was to interface a microcontroller to a real-time data acquisition system. We also wanted to complete a project that would have an appropriate mix of hardware (analog and digital) and software at both high and low levels. As a result, we decided to construct a simple and cheap scanning tunneling microscope that would be driven by an ATMega163 series microcontroller and operated from a PC.