Article pubs.acs.org/cm
Selective Growth of Titanium Nitride on HfO2 across Nanolines and Nanopillars Sonali N. Chopra, Zizhuo Zhang, Chris Kaihlanen, and John G. Ekerdt* McKetta Department of Chemical Engineering, The University of Texas at Austin, 200 East Dean Keeton Street, Stop C0400, Austin, Texas 78712, United States S Supporting Information *
ABSTRACT: This work targets the area selective atomic layer deposition (ASALD) of TiN onto HfO2 for use as the word line in a memory device. Unlike other patterning processes, AS-ALD eliminates etching steps and also allows for growth of patterned films with precise thickness control. This study investigates how AS-ALD differs on planar and nonplanar surfaces. Using a combination of X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy, we demonstrate a way to confer selectivity to a substrate using surface features. Self-assembled monolayers form defects at regions of high curvature, allowing nucleation of TiN films in ALD. This is in contrast to a treated planar surface with no features, which exhibits complete blocking of TiN up to a certain limit of ALD cycles.
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INTRODUCTION As device dimensions for integrated circuits continuously scale downward, significant focus has been devoted to developing alternate processes for the nanofabrication of functional structures with minimum dimensions of
