Selective Growth of Titanium Nitride on HfO₂ across Nanolines and Nanopillars

Abstract

This work targets the area selective atomic layer deposition (AS-ALD) of TiN onto HfO 2 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.

Nanoscale selective area atomic layer deposition of TiO2using e-beam patterned polymers

“…7, So far, majority of the AS-ALD studies have been performed using area-deactivated approach where mostly selfassembled monolayers (SAMs) are utilized as the growthblocking layers by covering the chemically reactive sites on the substrate and exposing non-reactive groups. 7,9,23,27,[29][30][31][32][33][34][35][36][37][38][39][40] Alkyl silanes e.g., alkyl trichlorosilanes, alkyl triethoxysilanes, etc. have been exploited as mono-layered surface modiers to block ALD nucleation of various metal oxide thin lms and metallic nanoparticles/thin lms.…”

Area‐Selective Atomic Layer Deposition Using Vapor Dosing of Short‐Chain Alkanethiol Inhibitors on Metal/Dielectric Surfaces

“…[ 16 ] However, when it comes to the formation of such bulky SAMs across complex 3D nanostructures with regions of high curvature, the presence of their steric hindrance appears to be a critically limiting factor to confer deposition selectivity, indicative of incompatibility with advanced 3D nanofabrication. [ 25 ]…”

“…[16] However, when it comes to the formation of such bulky SAMs across complex 3D nanostructures with regions of high curvature, the presence of their steric hindrance appears to be a critically limiting factor to confer deposition selectivity, indicative of incompatibility with advanced 3D nanofabrication. [25] To overcome the above-indicated limitations, many attempts have been made to enable facile and efficient surface modification through vapor-phase functionalization of small inhibitor molecules on non-growth areas. [1,4,7,17,26] Among them, surface alteration with vapor dosing of such short-chain aminosilanes showed promise toward rendering much smaller surface alkylating agents with short exposure times, making it more suitable for integration of AS-ALD in the complex and 3D nanostructures.…”

Inherently Area‐Selective Atomic Layer Deposition of SiO2 Thin Films to Confer Oxide Versus Nitride Selectivity

“…In semiconductor manufacturing, a top-down patterning method involving repeating lithography and etching steps chain length dependence causes steric hindrance when SAMs are placed on regions of high curvature in 3D nanostructures, therefore there is inherent selectivity loss in SAM-free regions, incompatible with advances in 3D bottom-up nanofabrication. [24] To overcome these limitations, we have developed alternative methods for surface modification compatible with high volume manufacturing of 3D nanostructures through vaporphase formation of small inhibitor molecules. Indeed, using ion implantation and short-chain alkylating agents, we successfully demonstrated topographical selectivity, albeit with limited deposition selectivity compared to long-chain SAMs.…”