Impact of Water Content in NMP on Ohmic Contacts in GaN HEMT Technologies
Autor: | Alexander Hugger, Aleksandra Dlugolecka, Raphael Ehrbrecht, Michael Hosch, Hermann Stieglauer |
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Rok vydání: | 2020 |
Předmět: |
0209 industrial biotechnology
Materials science Moisture business.industry Gallium nitride 02 engineering and technology High-electron-mobility transistor Condensed Matter Physics Industrial and Manufacturing Engineering Electronic Optical and Magnetic Materials Lift (force) chemistry.chemical_compound 020901 industrial engineering & automation chemistry Hygroscopy Optoelectronics Electrical and Electronic Engineering business Contact area Water content Ohmic contact |
Zdroj: | IEEE Transactions on Semiconductor Manufacturing. 33:552-556 |
ISSN: | 1558-2345 0894-6507 |
DOI: | 10.1109/tsm.2020.3028446 |
Popis: | Wet chemical lift off in N-Methyl-2-pyrrolidone (NMP) is widely used in GaN HEMT Front End manufacturing. In case of a Ti-Al-Ni-Au based metal stack for ohmic contacts, the quality of the lift-off process is a strong function of the water content in the solvent NMP. In this article, it will be shown that the metal stack can be attacked during lift off in NMP when its water content is exceeding 5%. Additionally, environmental impacts on the hygroscopy of NMP are investigated. Both temperature of NMP and its contact area to air impact the evolution of its water content. Based on these investigations, the lift off sequence was slightly adapted in order to keep moisture below a certain level and avoid optical defects on ohmic contacts. |
Databáze: | OpenAIRE |
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