AVS 61st International Symposium & Exhibition
    Electronic Materials and Processing Tuesday Sessions
       Session EM-TuP

Paper EM-TuP15
In Situ Metrology during GaN and InGaN Growth by Remote Plasma-assisted MOCVD

Tuesday, November 11, 2014, 6:30 pm, Room Hall D

Session: Electronic Materials and Processing Poster Session
Presenter: Daniel Seidlitz, Georgia State University
Authors: D. Seidlitz, Georgia State University
R.L. Samaraweera, Georgia State University
I.T. Ferguson, University of North Carolina at Charlotte
A. Hoffman, Technical University Berlin, Germany
N. Dietz, Georgia State University
Correspondent: Click to Email
Using real-time optical diagnostics during the GaN and InGaN growth progress in a remote plasma-assisted Metal Organic Chemical Vapor Deposition (RPA-MOCVD) reactor provides details in the precursors’ decomposition processes and epitaxial layer growth mechanisms. Growth process control provisions in the RPA-MOCVD reactor enable a temporal and spatial controlled injection of metal organics (MO) as well as nitrogen (N2) plasma activated hydride precursors such as hydrogen (H2) or ammonia (NH3). Remote activated hydride precursor fragments (e.g. N*/NH*/NH2*) are generated using a hallow cathode driven by a tunable radio frequency (rf) power source up to 600W. The radicals are directed to the substrate surface by the remote plasma afterglow regime. Plasma Emission Spectroscopy (PES) and UV-Absorption spectroscopy (UV-AS) are used to identify the active species in the plasma and determine their concentrations in dependence of the injected precursors N2, H2 and NH3. Plasma emission spectroscopy during the growth run allows also a time dependent recording of the quantitative behavior of the reactive particles inside the plasma. In addition, real-time measurements and analysis of reflection spectroscopy at normal incidence on the growth surface contribute sub-monolayer growth rates for GaN and InGaN. In this report we will present and discuss results of in-situ Plasma emission spectroscopy, UV-Absorption spectroscopy and Normal incidence reflection spectroscopy (NI-RS). The combination of these real-time characterization methods provides qualitative and quantitative identification of active species in the gas phase and determination of growth rates at the growth surface. The in-situ obtained growth rates are compared with ex-situ thickness measurements (e.g. Transmission and reflection spectroscopy) and results of layer structural characterization methods (Raman spectroscopy, PL). These studies will aid our understanding of how process growth parameter such as substrate temperature, plasma-assisted precursor generation/defragmentation, or the quantity of active species concentrations influence the growth and properties of binary and ternary group III-nitride alloys.