Patent ID: 6417673
Filing Date: 2002-07-09
Classification: G01N,G01Q,Y10S

Abstract:
An imaging system comprisingmeans for holding a sample to be probed, said sample comprising one or more semiconducting portions each characterized by a specified carrier concentration that imparts to each respective portion only a semiconducting electrical property, an active tip capable of exhibiting depletion effects and adapted to successively probe spaced-apart portions of said sample while in contact therewith, said tip comprising a semiconductor material having a semiconducting electrical property and being doped to exhibit a specified carrier concentration on the order of or less than the highest concentration of carriers in any semiconducting sample portion to be probed, the concentration of carriers in said tip being such as to maintain a semiconducting electrical property in said doped tip, means for applying a variable bias voltage of a specified polarity between said tip and said holding means to vary the voltage applied to said sample at each probed portion and to cause carriers to be depleted in said semiconducting tip away from the contact between said tip and the probed sample portion, means for positioning said tip overlying successive portions of said sample, and means for measuring the change in capacitance at each probed portion as the voltage applied thereto is varied.