Contactless, high-speed waveform measurements on gallium arsenideICs

A setup for photoemission testing, which compares favorably with results from electron-beam testing, particularly in terms of measurement time, is presented. The photoemission sampling system described has a unique detector design and a viewer for the added convenience of the equipment operator. performance results when this technique is used to measure delay and rise times on integrated gallium arsenide MESFET circuits are reported. The switching time of these circuits is around 200 ps. The system measures electrical pulses with an 8-ps rise time, so these GaAs circuits can be tested by the system. An interesting feature for special testing is the system's ability to activate devices within a chip by a pulsed visible light beam