Improved Electrostatic Discharge Protection for Semiconductor Chips
Original Publication Date: 1987-Nov-01
Included in the Prior Art Database: 2005-Feb-02
Many high density production semiconductor chips require electrostatic discharge (ESD) protection approach. An ESD diode is described in this article which can be incorporated into existing chip structures without added process steps. The breakdown voltage of this diode gives adequate base-to-emitter protection against ESD. Fig. 1 shows a cross-section of the disclosed ESD diode structure. Identified beginning at the top of the figure are:  p+ boron-doped polysilicon;  CVD oxide;  a boron outdiffusion from the p+ polysilicon;  an n+ phosphorous inplant;  n- epitaxy;  n+ silicon subcollector; and  a p- silicon substrate. The emitter and collector supplies are identified as  and , respectively.