Dense Trench Substrate Contact Process
Original Publication Date: 1985-Dec-01
Included in the Prior Art Database: 2005-Feb-19
A process for the formation of a dense trench substrate contact is provided which uses a mask that defines the contact and a metal pattern which shorts the substrate to an adjacent N+ region serving as the contact. In the process as shown in Fig. 1, a P- type semiconductor substrate 10 has an N- epitaxial layer 12 grown thereon with an N+ sub collector 14 disposed at the interface between layers 10 and 12. A contact-forming trench 16 and isolation trenches 18 and 20 are formed spaced from trench 16, with each extending through subcollector 14 to substrate 10. A thin layer 22 of silicon dioxide is grown on the upper surface of epitaxial layer 12 and on the exposed surfaces in trenches 16, 18 and 20 and a thin layer 24 of silicon nitride is deposited over layer 22.