The role of transient surface morphology on composition control in AlGaN layers and wells
- North Carolina State Univ., Raleigh, NC (United States)
- Adroit Materials, Inc., Cary, NC (United States)
- North Carolina State Univ., Raleigh, NC (United States); Adroit Materials, Inc., Cary, NC (United States)
The mechanisms governing “compositional pulling” during the growth of AlxGa1-xN wells are investigated. Gallium-rich AlxGa1-xN wells grown on high dislocation density AlN/sapphire templates exhibit asymmetric and diffuse composition profiles, while those grown on low dislocation density native AlN substrates do not. Furthermore, strain in all AlxGa1-xN wells is found to be pseudomorphic, ruling it out as the dominating driving force. Rather, the high threading dislocation density of the AlN template is considered to play the defining role. We propose that a transient surface morphology is introduced during dislocation mediated spiral growth, which, in conjunction with process supersaturation, determines the Ga incorporation. Finally, these findings provide insights into compositional pulling in high Ga content AlxGa1-xN grown on AlN and provide a route to grow thicker wells with very abrupt interfaces on native AlN substrates.
- Research Organization:
- Adroit Materials, Cary, NC (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); National Science Foundation (NSF); US Army Research Office (ARO); US Air Force Office of Scientific Research (AFOSR); US Department of the Navy, Office of Naval Research (ONR)
- Grant/Contract Number:
- SC0011883; ECCS-1508854; ECCS-1610992; DMR-1508191; ECCS-1653383; W911NF-15-2-0068; W911NF-16-C-0101; FA9550-17-1-0225; FA9550-14-1-0182; N62909-17-1-2004; DGE-1252376
- OSTI ID:
- 1611696
- Journal Information:
- Applied Physics Letters, Vol. 114, Issue 3; ISSN 0003-6951
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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