Method to Fabricate Self-Aligned Guard Ring Schottky Diodes
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-04
This article describes a sidewall procedure, the process steps of which are illustrated by Figs. 1 through 5, whereby self-aligned guard ring Schottky barrier diodes (SBDs) may be fabricated by conventional processing techniques and without the use of polysilicon or a high temperature metallurgy. The sidewall is wet etched to open a diffusion window for making the guard ring. Fig. 1 shows an N-type wafer bearing 1000 A of SiO2 and Si3N4, respectively, following a conventional photoresist stripping step. 300 A"Œ of SiO2 followed by a 300 A of Si3N4 are next grown on this structure, followed by a blanket reactive ion etch (RIE), with end- point detect at SiO2, to form the Si3N4 sidewalls shown in Fig. 2.