Scanning electron microscopy as a flexible technique for investigating the properties of UV-emitting nitride semiconductor thin films

C Trager-Cowan,P J Parbrook,G Naresh-Kumar,S Kraeusel,B Hourahine,R M Smith,M Nouf-Allehiani,A Knauer,S Vespucci,Y Zhang,W Avis,M Weyers,V Kueller,Y Gong,L Jiu,T Wang,P R Edwards,P A Shields,A Alasmari,Richard Johnston ,Matthew D Smith ,David Thomson ,Tim Wernicke ,Gunnar Kusch ,Christian Kühn ,Elena Pascal ,Johannes Enslin ,Frank Mehnke ,Jochen Bruckbauer ,Lucia Spasevski ,Sebastian Walde ,Robert Martin ,Pierre-Marie Coulon ,Sylvia Hagedorn ,Michael Kneissl ,Aimo Winkelmann

doi:10.1364/prj.7.000b73

Abstract

In this paper we describe the scanning electron microscopy techniques of electron backscatter diffraction, electron channeling contrast imaging, wavelength dispersive X-ray spectroscopy, and cathodoluminescence hyperspectral imaging. We present our recent results on the use of these non-destructive techniques to obtain information on the topography, crystal misorientation, defect distributions, composition, doping, and light emission from a range of UV-emitting nitride semiconductor structures. We aim to illustrate the developing capability of each of these techniques for understanding the properties of UV-emitting nitride semiconductors, and the benefits were appropriate, in combining the techniques.

Highlights

The scanning electron microscope (SEM) is a very powerful tool for investigating and imaging a wide range of material properties spanning topography, structure, composition, and light emission [1,2,3,4]
The electron channeling contrast imaging (ECCI) micrograph was acquired at an electron beam energy of 30 keV using the Sirion SEM
We have illustrated the capabilities of a range of non-destructive SEM techniques that can be used to provide complementary information on material properties encompassing topography, structure, composition, and light emission down to the nanoscale

Summary

Introduction

The scanning electron microscope (SEM) is a very powerful tool for investigating and imaging a wide range of material properties spanning topography, structure, composition, and light emission [1,2,3,4]. The light emission cathodoluminescence (CL) [15,16,17] and the current (electron beam-induced current) [1,17] generated when a high-energy electron beam is incident on a sample, provide valuable information on a sample’s luminescence and electrical properties, respectively. While each of these techniques individually provides valuable information, when one or more of these techniques are combined, they can provide invaluable complementary information. As we illustrate in this paper, it is possible to acquire an ECCI micrograph and a CL image for the same part of the sample to determine the influence of structural defects on a material’s light emission properties

Objectives

Results

Conclusion