Fabrication and Measurement of Lateral InAs Nanowire MOSFETs
| Autor: | Wei-Jin Li, 李維晉 |
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| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 In this thesis, we have fabricated the lateral InAs nanowire metal-oxide-semiconductor field-effect transistors. The nanowires are grown by molecular beam epitaxy. We use electron beam lithography to define gate length in hundreds of nanometers, and use atomic layer deposition technology to grow 10 nm Al2O3 as gate oxide. The reactive ion etching removes the aluminum oxide in the contact area. The electrode is composed of 30 nm Ti / 80 nm Au by electron beam evaporation. In order to improve the electrical properties of the device, we use wet etching with ammonia solution or ammonium sulfide solution to remove the nanowire native oxide layer. After the electrode is completed and the rapid thermal annealing at 420 ℃ is used to reduce the contact resistance. In the electrical measurement, we study the effect of wet etching on the native oxide layer and the thermal annealing, respectively. The transmission line method is used to analyze the contact resistance and the results are compared with those in the literature. In the part of the transistor characteristics, we found that the transistors obviously could not turn off. It is speculated that the gate structure and the surface states may lead to insufficient gate control force. The change of the gate switching rate confirms the existence of the surface states of the nanowires. Finally, we discuss how to modify processing technologies in order to improve the electrical properties of nanowire transistors in the future. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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