Recessed Oxide Process to Reduce Field Doping Encroachment
Original Publication Date: 1986-May-01
Included in the Prior Art Database: 2005-Mar-09
A method is described to very simply create a controlled offset between the field doping and the edge of an active device in a recessed oxide (ROX) process. The method results in reduction of narrow channel effects, reduced device perimeter capacitance, and an increased junction breakdown voltage. Referring to Fig. 1, a thin thermal oxide 2 and a silicon nitride film 4 are first formed on a silicon substrate 6. A photoresist layer 8 is applied and patterned to define the offset field implant regions 9. The silicon nitride 4 is then plasma etched using the photoresist layer 8as an etching mask. Field implant 10 is then performed using the same photoresist 8 as an implant mask.