Title :
The influence of substrate atomic step morphology on threading dislocation distributions in iii-nitride films
Author :
Picard, Yoosuf N. ; Caldwell, Joshua D. ; Twigg, Mark E. ; Eddy, Chip R., Jr. ; Mastro, Michael A. ; Henry, Richard L. ; Holm, Ronald T. ; Neudeck, Philip G. ; Trunek, Andrew J. ; Powell, J.Anthony
Author_Institution :
Naval Res. Lab., Washington
Abstract :
In this study, we investigated the influence of atomic step morphologies of 4H-SiC surfaces on the distribution of threading edge and screw dislocations in GaN films grown by MOCVD. Electron channeling contrast imaging (ECCI) was implemented to profile engineered 4H-SiC mesas. Two types of atomic morphologies were consistently observed at these mesa surfaces. Mesa surfaces with no screw dislocations exhibited purely atomic step-free surfaces except within 2-20 mum of the mesa edges. Mesas penetrated by at least one screw dislocation exhibited a uniform though highly stepped atomic surface across the entire mesa.
Keywords :
III-V semiconductors; MOCVD; channelling; edge dislocations; gallium compounds; screw dislocations; semiconductor thin films; silicon compounds; surface morphology; wide band gap semiconductors; 4H-SiC surfaces; ECCI; GaN; III-nitride films; MOCVD; SiC; electron channeling contrast imaging; mesa edge surfaces; substrate atomic step morphology; threading edge dislocation distribution; threading screw dislocation distribution; Educational institutions; Electrons; Fasteners; Fluctuations; Gallium nitride; NASA; Physics; Space technology; Substrates; Surface morphology;
Conference_Titel :
Semiconductor Device Research Symposium, 2007 International
Conference_Location :
College Park, MD
Print_ISBN :
978-1-4244-1892-3
Electronic_ISBN :
978-1-4244-1892-3
DOI :
10.1109/ISDRS.2007.4422505
