Schottky Diode With Narrow Self Aligning Guard Ring
Original Publication Date: 1982-Aug-01
Included in the Prior Art Database: 2005-Feb-10
The current-voltage characteristics of a metal to silicon Schottky barrier diode are considerably improved by forming a P-type diffused guard ring around the perimeter of the metal contact. A process for forming a narrow self aligning guard ring using ion implantation includes the following: 1. Define the diode area by opening a window in the silicon dioxide layer 10 over the N epitaxial layer 11. 2. Deposit a dissimilar material layer 12, such as silicon nitride, which can be selectively etched and etch in CF(2)/H(2) plasma or in some other anisotropic etching gas to substantially remove the horizontal portion of the layer 12 and leave the vertical portion of layer 12, as shown in Fig. 1. 3. Deposit platinum (Pt) and sinter to form PtSi Schottky contact 14.