Inherently Area-Selective Atomic Layer Deposition of Manganese Oxide through Electronegativity-Induced Adsorption.

Yi-Cheng Li,Yu-Xiao Lan,Yan-Wei Wen,Jing-Ming Zhang,Rong Chen,Bin Shan,Kun Cao,Miao Gong

doi:10.3390/molecules26103056

Abstract

Manganese oxide (MnOx) shows great potential in the areas of nano-electronics, magnetic devices and so on. Since the characteristics of precise thickness control at the atomic level and self-align lateral patterning, area-selective deposition (ASD) of the MnOx films can be used in some key steps of nanomanufacturing. In this work, MnOx films are deposited on Pt, Cu and SiO2 substrates using Mn(EtCp)2 and H2O over a temperature range of 80–215 °C. Inherently area-selective atomic layer deposition (ALD) of MnOx is successfully achieved on metal/SiO2 patterns. The selectivity improves with increasing deposition temperature within the ALD window. Moreover, it is demonstrated that with the decrease of electronegativity differences between M (M = Si, Cu and Pt) and O, the chemisorption energy barrier decreases, which affects the initial nucleation rate. The inherent ASD aroused by the electronegativity differences shows a possible method for further development and prediction of ASD processes.

Highlights

Area-selective deposition (ASD), including area-selective atomic layer deposition (ALD), is considered a prospective way to downscale nano-electronics [1,2,3]
After 50 ALD Manganese oxide (MnOx) cycles, the amplified border areas are characterized with SEM and EDS
The differences in electronegativity may become a supplemental explanation of selectivity for some precursors on certain substrates

Summary

Introduction

Area-selective deposition (ASD), including area-selective atomic layer deposition (ALD), is considered a prospective way to downscale nano-electronics [1,2,3]. ALD takes advantage of self-limiting reactions to achieve conformal thin film growth with atomic-level thickness control [4]. The ALD reactions are extremely sensitive to surface chemistry due to the self-limiting nature [5]. The activity of the precursors and steric hindrance from the ligands affect the density of chemisorption [6]. The type and density of surface-active sites have an important role in the growth rate of target materials [7]. Ideal area-selective ALD can be realized through nuclei inhibition on the nongrowth areas. Prior reports showed that the selectivity could be obtained by chemical modification, including surface passivation with polymers, self-assembled monolayers (SAMs), inhibitors and so on [15,16,17]

Methods

Results

Conclusion