J.R. Thompson, Yang Ren Sun, et al.
Physica A: Statistical Mechanics and its Applications
This paper describes improvements in the self-aligned contact process for 0.150 μm and 0.175 μm technology generations. Using a dynamic random access memory cell layout, we show that self-aligned contacts can be formed at 0.175 μm ground rules and beyond by using a C4F8-CH2F2 chemistry. With the improved etch selectivity, gate cap nitride thickness can be reduced, resulting in a smaller aspect ratio for the gate etch, borophosphosilicate glass fill, and contact etch. With a rectangular contact, the area can be increased and the process windows for lithography and etch are improved. The process window for lithography increases by up to 40%, the aspect ratio for the etch and the contact fill is less, and the sensitivity to misalignment is reduced. The combination of rectangular contacts and C4F8-CH2F2 chemistry greatly enhances the product yield.
J.R. Thompson, Yang Ren Sun, et al.
Physica A: Statistical Mechanics and its Applications
K.N. Tu
Materials Science and Engineering: A
Shu-Jen Han, Dharmendar Reddy, et al.
ACS Nano
Mark W. Dowley
Solid State Communications