Scanning Tunneling Microscope Instrumentation for Introductory Electronics and Materials Characterization Courses

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Courses Scanning tunneling microscope technology (STM) is being used as a unifying project in our introductory electronics course and as a bridge to our laboratory course in materials characterization techniques. By having the students build an STM and the compare their homebuilt version with a commercial unit, we address two major problems endemic to electronics courses: the failure to truly interest students in the wide range of circuit techniques presented and the lack of student exposure to the full scope of a complex design project. We have chosen the STM because of its intuitive appeal and range of applications engage our students who come from a variety of scientific backgrounds. We are building 13 scanning tunneling microscope workstations, each consisting of several separate circuit modules. In weekly laboratory sessions students breadboard and study the circuits in each module, then interconnect previously built units to make a working STM. The classroom lectures use the performance requirements of the STM project as a guide to exploring component and circuit specifications. We have purchased a commercial instructional STM which the students use after they have demonstrated their homebuilt version. They gain an appreciation of the results of the development efforts of an expert team and come to understand that a complex instrument is composed of simpler subunits. Most students who take the electronics course subsequently take the materials characterization laboratory course. They study the physics of scanning tunneling microscopy in experiments using the commercial STM, which complements present experiments in x-ray diffraction and scanning electron microscopy. This is excellent preparation for independent research projects with active graduate research programs in scanning probe microscopies. Students pursuing these courses have thorough knowledge of a state-of-the-art instrument and technique which gives them confidence to master any technology they will encounter in the future.