Correlation of threading screw dislocation density to GaN 2‐DEG mobility

• Published in: Electronics letters Vol. 50; no. 23; pp. 1722 - 1724
• Main Authors: Hite, J.K., Gaddipati, P., Meyer, D.J., Mastro, M.A., Eddy, C.R.
• Format: Journal Article
• Language: English
• Published: Stevenage The Institution of Engineering and Technology 06.11.2014; John Wiley & Sons, Inc
• Subjects: 2‐DEG mobility; AlGaN‐GaN; Aluminium; aluminium compounds; Aluminum; channelling; Correlation; Density; Dislocation density; ECCI; electron channelling contrast imaging; electron mobility; gallium compounds; Gallium nitrides; Hall effect; Hall effect test structures; HEMT; Heterostructures; high electron mobility transistors; III‐V semiconductors; Nitrides; Screw dislocations; threading screw dislocation density; two‐dimensional electron gas; wide band gap semiconductors
• ISSN: 1350-911X; 0013-5194; 1350-911X
• DOI: 10.1049/el.2014.2401

A direct correlation between local threading screw dislocation densities in an aluminium gallium nitride/gallium nitride (AlGaN/GaN) heterostructure and the mobility of electrons in the two‐dimensional electron gas (2‐DEG) formed at the interface of that heterostructure is presented. Threading screw dislocations are directly imaged through open areas of Hall‐effect test structures using electron channelling contrast imaging. The dislocation density measured for a given test structure is correlated to the mobility of the same structure. The results show a direct, negative correlation between mobility and screw/mixed dislocation density.