碩士 / 國立清華大學 / 工程與系統科學系 / 107 / Electrical characteristics and interface layer quality can be improved, and leakage current can be reduced in FinFET by appropriate activation process. The drain current can be enhanced and reverse current of junction can be decreased by suitable depth of ion implantation. Doping activation and ion implantation always play important roles in electrical characteristics of FinFET. In this thesis, far infrared light(10.6μm) and visible green light(532nm) were used for annealing dopants. The short wavelength of green light is used to activate the surface layer, and the far infrared light is intended to activate deeper region of source-drain. Laser annealing is expected to reduce the defects, which are generally caused by traditional rapid thermal annealing. Double ion implantations include a deep junction with Phosphorus to reduce junction leakage, and a shallow junction with Arsenic to provide sufficient channel carrier at inversion.
On the first part of the thesis, laser annealing with two wavelengths and rapid thermal annealing are applied to the thermal budget of fabrication process, which may suppress leakage current caused by diffusion after high temperature. It is known that the roughness of gate dielectric are less after laser annealing treatment. The experimental results show that the excellent electrical characteristics of FinFET are obtained such as the drain current (4.011x10-5 A/μm), the maximum transconductance value (38.66 μA/V) and the sub-threshold swing characteristics (about 68.7 V/dec) after red and green laser annealing. Electrical properties of FinFET with laser annealing using two wavelengths are much improved as compared to these with traditional thermal annealing.
In the second part, double ion implantations method are studied to increase on current of MOSFET, so five devices with different implantation parameters are designed. The surface is pre-amorphized by Phosphorus implantation, and then the shallow junction is formed by an Arsenic ion implantation. The junction leakage current of device with double ion implantations is lower than that with single one. The variation of threshold voltage with double ion implantations is more stable than that with single one.
The on/off ratio of device with double ion implantations is poor as found in previous part. In the third part, various implantation energy for both shallow and deep dopants on SOI FinFET are investigated to reduce the leakage current and keep large drain current. The results show that FinFET with S/D junction formed by phosphorus 40keV/arsenic 40keV has the highest drain current (6.814 x10-5 A/μm), on/off ratio (1.234 x108), maximum transconductance value (49.36μA/V), it is also found that double ion implantation can further improve the on current characteristics.
| Identifer | oai:union.ndltd.org:TW/107NTHU5593006 |
| Date | January 2018 |
| Creators | Chen, Meng-Yang., 陳孟揚 |
| Contributors | ChangLiao, Kuei-Shu, 張廖貴術 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 88 |
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