Influence of technological factors on the characteristics of ohmic contacts of powerful AlGaN/GaN/SiC HEMT
Open Access
- 31 October 2019
- journal article
- Published by National University of Science and Technology MISiS in Materials of Electronics Engineering
- Vol. 21 (3), 182-193
- https://doi.org/10.17073/1609-3577-2018-3-182-193
Abstract
In this paper are considers the effect of the microrelief, dislocation structure and other defects of the epitaxial layers of the source and drain regions of the nitride HEMT transistors on the parameters of the formed ohmic contacts. The studies were carried out directly on high−power microwave transistors made of GaN/AlGaN/GaN/SiC heterostructures. Ohmic burning contacts were formed using the compositions Ti—Al—Mo—Au and Ti—Al—Ni—Au. To estimation the structural features of the contact areas, the surface microrelief at the interface of the burned contact/AlGaN and the defects formed on its surface was studied. It is shown that the resistance of the source and drain regions is largely determined by the surface microstructure at the boundary. Experimentally shown is the formation of a conducting layer in AlGaN under the ohmic contacts. The possibility of the formation of a new type of structural defects with a high aspect ratio in the contact and active areas of the devices during the formation of ohmic burned contacts is demonstrated. It is shown that the appearance of high densities of such defects leads to an increase of the device leakage currents.Keywords
This publication has 13 references indexed in Scilit:
- Planar Ohmic Contacts to Al0.45Ga0.55N/Al0.3Ga0.7N High Electron Mobility TransistorsECS Journal of Solid State Science and Technology, 2017
- Ohmic contacts to Gallium Nitride materialsApplied Surface Science, 2016
- Characterization of interface reaction of Ti/Al-based ohmic contacts on AlGaN/GaN epitaxial layers on GaN substrateJapanese Journal of Applied Physics, 2016
- Nitride HEMTs vs arsenides: The ultimate battle?Modern Electronic Materials, 2016
- Degradation mechanisms of Ti/Al/Ni/Au-based Ohmic contacts on AlGaN/GaN HEMTsJournal of Vacuum Science & Technology B, 2015
- Ti/Al ohmic contacts on AlGaN/GaN heterostructures with different defect densityApplied Surface Science, 2014
- Low-Contact-Resistance Non-Gold Ta/Si/Ti/Al/Ni/Ta Ohmic Contacts on Undoped AlGaN/GaN High-Electron-Mobility Transistors Grown on SiliconApplied Physics Express, 2013
- Temperature dependence of Ohmic contact characteristics in AlGaN/GaN high electron mobility transistors from −50 to 200 °CApplied Physics Letters, 2009
- Handbook of Nitride Semiconductors and DevicesPublished by Wiley ,2008
- Short-Channel Effect Limitations on High-Frequency Operation of AlGaN/GaN HEMTs for T-Gate DevicesIEEE Transactions on Electron Devices, 2007