annealing temperature can be any value from 300 u00b0 c to 700 u00b0 c it has been observed however that best results occur with an annealing temperature of 450 u00b0 c to 550 u00b0 c the function of the annealing operation is to form a layer of iridium silicide irsi on the silicon substrate during the annealing operation any impurities at the irsi interface are taken up into the irsi lattice and an atomically clean interface exists between the two materials atomic cleanliness is important because impurities such as oxides or carbon at the interface can act as an insulator between the iridium and silicon and will cause the barrier height to vary and the stability of the entire detector to be adversely affected guard rings 8 of n type material such as arsenic are implanted at the extremeties of the diode active imaging area this region acts as a block to any surface currents which might occur and it also eliminates edge effects caused by the manufacture of the sintered irsi layer these two phenonena are extremely detrimental to the operation of the detector under reverse bias conditions because they are the major source of leakage current elimination of reverse leakage allows the device to be operated at a reverse bias of 10 or more volts a silicon dioxide protective layer 9 may be formed from the guard rings 8 to the edges of the silicon substrate 4 aluminum contacts 10 are then made to both the substrate 4 and the iridium layer 6 and electrodes 12 and 14 are bonded to the top and bottom aluminum contacts 10 to complete the schottky barrier device the preferred mode of operation as shown in fig1 is to illuminate the barrier from the.