CONTACTLESS DETECTION OF OPTICAL INDUCED CURRENT IN MICROELECTRONIC DEVICES BY CAPACITIVE COUPLING

The capacitive coupling of transient voltages into an electrode was us ed for the contactless detection of electrical pulses as on bonded IC' s using a laser scanning microscope as on wafers using a needle prober . The spatial resolution was found very sensitive to the screening of the electrode. The signal strength was measured as a function of the l oad resistance of the illuminated pn-junction. The diffusion length an d carrier life time could be measured simultaneously. The carrier mobi lity calculated on this base agrees with the values known from literat ure.