Spreadsheets to promote interactive engagement in semiconductor device courses

The development and initial implementation of a prototype "virtual laboratory" based on Microsoft® Excel spreadsheets with associated Visual Basic® for Applications modules is described for use in semiconductor device courses for engineering undergraduates. The spreadsheets use graphical methods to illustrate quantities such as charge densities, electric field profiles, electrostatic potentials, energy band diagrams, carrier concentrations, current density plots, and related quantities for various semiconductor devices, including pn junctions, bipolar junction transistors, MOS capacitors (including both electrostatics and capacitance-voltage characteristics), MOSFETs, and also for semiconductor statistics. The students can use scrollbars and other ActiveX® controls interactively to adjust device parameters such as doping levels, applied bias voltages, layer widths, and temperature, and immediately visualize the effects of those changes on the device behavior. Interactive exercises using these spreadsheets have also been developed. The initial use and assessment of these tools using student examination and homework scores, student teaching evaluations, focus groups, and a special web-based Device Concept Inventory developed in this project are described.