Method and means for optical detection of charge density modulation in a semiconductor

摘要

Disclosed is a technique for probing dynamic sheet charge density variations in integrated semiconductor devices. Using a specially designed non-invasive Nomarski phase contrast interferometer a sheet charge density sensitivity of 2.6x108 e/cm2/ 2ROOT Hz is extracted from experimental data for 1 mA of detected photocurrent. The charge density sensitivity makes possible mu V signal level detection in an active device, and with digital signals the corresponding signal/noise level is sufficiently high that multi-mega-baud data can be captured in real time.