METHOD OF MINIMIZING Al-Si ALLOYING IN SEMICONDUCTOR DEVICES
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
Disclosed is a method to minimize Al penetration in semiconductor devices which otherwise leads to yield loss due to emitter-base and Schottky barrier diode (SBD) leakage. Per this method, the Al-Cu in the contacts is oxidized to form an Al2O3 passivation layer. In conventional processing, a gap is formed around device contact (Image Omitted) windows in barrier metallurgy as a consequence of nitride hole formation and subsequent undercut from glass etchants. The structure of the device is indicated in Fig. 1A which shows the underlying Si 1, a PtSi layer 2 covered by a Cr/Cr2O3 layer 3 which also covers the Si3N4 layer 4. The SiO2 in the device is indicated by 5. The barrier gap 6 may provide a channel by which the Al-Cu metallurgy 7 may make contact with the underlying PtSi or the silicon substrate.