Electron beam-induced deposition of platinum from Pt(CO)2Cl2 and Pt(CO)2Br2.

Aya Mahgoub,Titel Jurca,Howard Fairbrother,Lisa Mcelwee-White,Rachel M Thorman,Cornelis W Hagen,Konstantin Preradovic,Hang Lu

doi:10.3762/bjnano.11.161

Abstract

Two platinum precursors, Pt(CO)2Cl2 and Pt(CO)2Br2, were designed for focused electron beam-induced deposition (FEBID) with the aim of producing platinum deposits of higher purity than those deposited from commercially available precursors. In this work, we present the first deposition experiments in a scanning electron microscope (SEM), wherein series of pillars were successfully grown from both precursors. The growth of the pillars was studied as a function of the electron dose and compared to deposits grown from the commercially available precursor MeCpPtMe3. The composition of the deposits was determined using energy-dispersive X-ray spectroscopy (EDX) and compared to the composition of deposits from MeCpPtMe3, as well as deposits made in an ultrahigh-vacuum (UHV) environment. A slight increase in metal content and a higher growth rate are achieved in the SEM for deposits from Pt(CO)2Cl2 compared to MeCpPtMe3. However, deposits made from Pt(CO)2Br2 show slightly less metal content and a lower growth rate compared to MeCpPtMe3. With both Pt(CO)2Cl2 and Pt(CO)2Br2, a marked difference in composition was found between deposits made in the SEM and deposits made in UHV. In addition to Pt, the UHV deposits contained halogen species and little or no carbon, while the SEM deposits contained only small amounts of halogen species but high carbon content. Results from this study highlight the effect that deposition conditions can have on the composition of deposits created by FEBID.

Highlights

Focused electron beam-induced deposition (FEBID) is a directwrite nanopatterning technique
In the work presented here, Pt(CO)2Cl2 and Pt(CO)2Br2 were used for FEBID in a regular scanning electron microscope (SEM) and Pt(CO)2Br2 was used for deposition in the aforementioned Auger electron spectroscopy (AES) setup
The main conclusion of this study is that the two compounds Pt(CO)2Cl2 and Pt(CO)2Br2 can both be successfully used as FEBID precursors to make platinum containing deposits

Summary

Introduction

Focused electron beam-induced deposition (FEBID) is a directwrite nanopatterning technique. At specific locations on the substrate exposed to the electron beam, the transiently adsorbed precursor molecules decompose, forming a deposit while the volatile byproducts of the reaction desorb into the vacuum [4,5,6,7]. In the work presented here, Pt(CO)2Cl2 and Pt(CO)2Br2 were used for FEBID in a regular scanning electron microscope (SEM) and Pt(CO)2Br2 was used for deposition in the aforementioned AES setup. The typical issues to be addressed when testing novel precursors include: (i) precursor storage, (ii) gas injection system (GIS) loading, (iii) optimal precursor temperature for deposition, (iv) precursor volatility and transport from the SEM chamber, (v) ability of precursor to form solid deposits upon electron exposure, and (vi) deposition rate and deposit composition. We report an investigation of these practical aspects of Pt(CO)2Cl2 and Pt(CO)2Br2 in the context of their potential use in FEBID of Pt nanostructures

Objectives

Results

Conclusion