APPLICATION OF CO2 LASER BEAM FOR FABRICATION OF SEMICONDUCTOR DIODE.

A medium power CO//2 laser has been used to fabricate an ohmic contact between an Au(Sb) layer and a high resistivity (1K OMEGA -cm) cm) n-Si substrate. This Au(Sb) layer is made on the lapped n-Si substrate by vacuum evaporation. When the interface of them is irradiated by the laser beam passing through the n-Si substrate, an n ** plus layer is formed on the Si substrate by the laser energy. This method is applied to fabrication of the large area surface barrier diode such as Au-Si nuclear detectors. By preparing the n** plus layer, reverse currents of this diode are remarkably reduced as compared with these of the detector made by a conventional lapping method. From extrapolation of saturation currents, the Schottky barrier height of this diode is estimated to 0. 8 eV.