Voltage waveforms in semiconductor devices using electric field induced second harmonic generation

Summary form only given. Evaluation of fast semiconductor devices requires both high temporal resolution and the ability to probe internal points of an IC noninvasively. While optical methods are suitable for this application, centrosymmetric semiconductors such as silicon and germanium require an external electro-optic probe placed within the fringe electric field flux lines of the region of interest, reducing sensitivity and adding parasitic capacitance to the probed circuit. In this work, we apply electric field induced second harmonic generation (EFISHG) to the measurement of voltage waveforms in the active region of GaN semiconductor devices without the use of any external electrooptic probe. The electronic pulse measured across the p-n junction is shown as a function of junction bias voltage (DC). As the junction becomes more forward biased, the diffusion capacitance increases, reducing the voltage drop of the high-speed pulse (<1 ns). The EFISHG signal due to the applied voltage is heterodyned with a background EFISHG signal caused by the piezoelectric fields present in GaN. As a result, the measured EFISHG signal appears linear in applied voltage. These results demonstrate it is possible to monitor an electric field within the device using EFISHG. Ultimately, we hope to use this technique to probe silicon-based integrated circuits using infrared light.