Fabrication of U-GaN and InGaN MOSFETs
碩士 === 國立清華大學 === 電子工程研究所 === 98 === This thesis investigates the fabrication of GaN MOSFETs utilizing Si as the implant species for the source and drain regions. In order to prevent nitrogen loss from the surface while keep ion implantation activation efficiency, we find the best annealing process...
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| Format: | Others |
| Language: | zh-TW |
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2009
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| Online Access: | http://ndltd.ncl.edu.tw/handle/58340536899178967574 |
| Summary: | 碩士 === 國立清華大學 === 電子工程研究所 === 98 === This thesis investigates the fabrication of GaN MOSFETs utilizing Si as the implant species for the source and drain regions. In order to prevent nitrogen loss from the surface while keep ion implantation activation efficiency, we find the best annealing process is to perform RTA at 1200 ℃ for 5 minutes in N2 ambient. The measured sheet resistance is as low as 62Ω/ohm. We investigated the performance of ALD deposited Al2O3 as the gate dielectric. To prevent Al2O3 being recrystallized during high temperature annealing, the ohmic contacts are formed before gate oxide deposition. The devices are forming gas annealed to further improve the oxide-GaN interface. The best measured RON is 24 Ω*cm and the current density above 10 mA/mm.
We also studied MOSFETs using InGaN/GaN material system. It is found that even the activation temperature is as high as 1100 ℃, the ION(max) is only about 1mA/mm due to poor activation in the source and drain. These devices exhibit significant drain leakage current which is attributed to substrate leakage current.
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