High-purity silicon sensor array for imaging soft X-ray and infrared radiation

A 256-element radiation sensor array with separate x- and y-readout addresses, fabricated on high-purity silicon (4 k Omega -cm) utilizing only standard integrated-circuit processing technologies, is presented. The design of the 16*16 array of 250*250 mu m/sup 2/ elements emulates that of successful precursors. The principle of operation of the sensor is based on the capacitive coupling of the elements in a matrix of sensing diodes. Two-dimensional position resolution is achieved through the direct collection of radiation-generated charge in the x-dimension and through the indirect capacitive coupling of this charge in the y-dimension. The design is an improvement over its predecessor (see S.A. Audet et al., 1989), which utilized polysilicon structures to resistively couple the columnar elements. Optimization of the readout electronics resulted in a charge-collection deficit of less than 1% at the x-addressed outputs, eliminating the need for the polysilicon structures and improving the energy and position resolutions of the modified sensor array. Experimental results demonstrated good sensor characteristics and confirmed two-dimensional position resolution of incident radiation with minimal crosstalk.<>