X-ray spectrometer by aluminum thermomigration

An x-ray array has been fabricated utilizing thermomigration of aluminum to form "deep diodes" through a 375 micron wafer with a lateral post spreading of less than 20 microns. The problem in depleting large thicknesses of silicon for detection of 1 to 50 Kev x-rays is eliminated. Low leakage detectors with full width half maximum system noise values of about 700 ev were obtained with a significant part of system noise due to the preamplifier. Reverse breakdowns measured at 1 microamp were over 300 volts. The new spectrometer offers a direction other than CCDs for extending x-ray detection with good spatial resolution to the 1 to 50 Key range.