Polycrystalline Silicon Contact to the High Barrier SBD
Original Publication Date: 1987-Feb-01
Included in the Prior Art Database: 2005-Jan-31
Disclosed is a method of making Schottky barrier diodes (SBDs) with P+ guard rings that may be wired up at the N+ polysilicon layer used for the emitter in semiconductor devices. This makes it possible to free up some wiring channels at the first level metal for other purposes. An enhancement of the method also makes it possible to short the junction between P+ polysilicon and N+ polysilicon layers with a self- aligned silicide strap. (Image Omitted) In the process, existing lithography and reactive ion etch are used on a previous photolevel (L1) to define the anode through the SiO2/Si3N4 stack 2 (Fig. 1). Polysilicon-emitter lithography (level L2) is used on the photoresist 1 to define the annular ring of N+ polysilicon 3. The overetch of level L2 (Fig.