Theoretical work and software simulation indicate the potential to use light to change transistor threshold values. By this technique a circuit can be placed into a mode ready for testing, with all switching devices activated to the same voltage level. In this research, the logical and electrical behavior of MOS transistors as the optical effect changes threshold values is being studied. Also being studied are changes in the electrical properties of switching devices (inverters and transmission gates) due to optical effects. Experiments on fabricated devices to determine if a stable optical threshold control can be designed are being performed. Also being investigated are methods of detecting the presence of defects through changes in signals at the output lines. This proposal was submitted under the Small Grants for Exploratory Research Program.
