Influence of Large-Aspect-Ratio Surface Roughness on Electrical Characteristics of AlGaN/AlN/GaN HFETs
2012 (English)In: IEEE transactions on device and materials reliability, ISSN 1530-4388, Vol. 12, no 3, 538-546 p.Article in journal (Refereed) Published
The effect of large-aspect-ratio surface roughness of AlGaN/GaN wafers is investigated. The roughness has a surface morphology consisting of hexagonal peaks with maximum peak-to-valley height of more than 100 nm and lateral peak-to-peak distance between 25 and 100 mu m. Two epitaxial wafers grown at the same time on SiC substrates having different surface orientation and with a resulting difference in AlGaN surface roughness are investigated. Almost no difference is seen in the electrical characteristics of the materials, and the electrical uniformity of the rough material is comparable to that of the smoother material. The reliability of heterostructure field-effect transistors from both materials have been tested by stressing devices for up to 100 h without any significant degradation. No critical effect, from the surface roughness, on device fabrication is experienced, with the exception that the roughness will directly interfere with step-height measurements.
Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE) , 2012. Vol. 12, no 3, 538-546 p.
Heterostructures, surface orientation (SO), surface roughness
National CategoryEngineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-84345DOI: 10.1109/TDMR.2012.2188403ISI: 000308461300001OAI: oai:DiVA.org:liu-84345DiVA: diva2:558789
Funding Agencies|Swedish Foundation for Strategic Research (SSF)||Swedish Governmental Agency of Innovation Systems (VINNOVA)||Swedish Energy Agency (STEM)||Chalmers University of Technology||Ericsson AB||Furuno Electric Co. Ltd.||Infineon AG||Norse Semiconductor Laboratories AB||Norstel AB||NXP Semiconductors BV||Saab AB||2012-10-052012-10-052012-10-05