Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8035170 | Thin Solid Films | 2014 | 5 Pages |
Abstract
A study on defect states in relatively low-carbon doped GaN is presented. A large current collapse was observed in AlGaN/GaN high electron mobility transistor (HEMT) operation when the device channel was doped with carbon of 1 Ã 1017 cmâ 3. Deep level transient spectroscopy measurements showed a positive and even negative correlation between the densities of carbon and those of shallow trap states. Along with their small concentrations, shallow traps could not be associated with the collapse of the HEMT. Photo capacitance measurements yielded large signal at very deep levels of 1.6 and 2.4 eV in carbon doped GaN. Especially, the 2.4 eV deep trap was estimated to be acceptor type and related to some indirect states that the minority carrier transient spectroscopy could not characterize. A 20% of doped carbon was allocated to the very deep traps, and the large current collapse was attributed to these carbon-related states.
Related Topics
Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
Takeshi Tanaka, Kenji Shiojima, Yohei Otoki, Yutaka Tokuda,