A compact self-shielding prober for accurate measurement of on-wafer electron devices

A compact self-shielding prober is proposed for measuring low-current-voltage characteristics of on-wafer electron devices. In the prober, a wafer and a wafer stage are set in a very small shielded region mostly enclosed by a plane top-board, a wafer-stage shield, and a sidewall shielding ring. A current of less than a picoampere can easily be measured without any shielding box. A prober designed to observe all devices on 4-in wafers can be as small as 27 cm×27 cm×12 cm. High-speed input/output waveforms of on-wafer large scale integrated circuits (LSIs) observed with this prober are as clear as those of packaged LSIs observed directly