Nitride Limited Schottky Barrier Diode Design
Original Publication Date: 1980-Jan-01
Included in the Prior Art Database: 2005-Feb-13
A number of conventional bipolar device fabrication processes include nitride-defined Schottky barrier diodes for use as antisaturation clamps and for other circuit functions. A wet-etch is performed through a hole in the nitride to define the active contact area within the underlying oxide. As shown in Fig. 1, lateral etching of the oxide yields a profile that is considerably wider than the defining nitride opening. This nitride hole, however, defines the active metal semi-conductor contact area by shadow masking. As shown in Fig. 1 an annular perimeter area results which is neither covered by metal nor by SiO(2). It is this unpassivated and unstablized area that gives rise to stability and long term reliability problems.