Infrared Response of Impurity Doped Silicon MOSFET's: Experimental Characterization of the Infrared Response of Gold Doped Silicon MOSFET's (IRFET's)

Abstract

has been observed and characterized using the gold acceptor level and gold donor level in the near infrared wavelength range from 1.0 to 3.0 microns. It will be shovrt from pulsed capacitance measurements on MOS capacitors and from measurement of the IRFET response that the characteristics of the gold impurity center in the surface space charge region correspond to the results observe| previously for the center in bulk silicon. Operation of the IRFE can then be described on the basis of a simple model where the change in charge state of the impurity cente r in the surface space charge region due to photoionization modulates the threshold voltage of the MOSFET and thus conductance of the device. The IRFET has a very high gain and responsivities of 10 milliwatts/tnicrojoule are easily achieved. Standard silicon MOSFET technology is employed and it should be possible to use other impurity centers to extend the response out to a wavelength of 14 microns. Applications in large scale integrated infrared imaging and target tracking arrays are anticipated. Unclassified SECUBITY CLASSIFICATION OF THIS PAGEflWl«! O.i» Fn'...<JI 1.1 ipWW^mWW^IIiy «*MI*«P^'W-!WM,..l«.' v»' l l-lWI .m ^wmmm'iiw'imvmmm». ^m^kwm^w^mi..-iH.^^ii V^t^« ii^ «-■-it^,^.