碩士 / 國立清華大學 / 工程與系統科學系 / 104 / When transistors’ feature sizes scale down lower than 20 nm, conventional MOSFET confront some issues such as the effects of subthreshold leakage, gate leakage, and so on. These issues can be resolved by FinFET structure. The electrical characteristics of FinFET can be bettter if its channel shape is high and thin. Effects of hydrogen plasma and high temperature treatment are studied in this thesis. When hydrogen plasma treatment is aplied on silicon surface, a slight etching could make channel more vertical, namely trimming, and enhances electrical characteristics of device. Moreover, when a high temperature treatment is applied on silicon, channel surface would become smoother, which reduces corona discharge and improves electrical characteristics.
In the first part, SOI n-FinFET is successfully fabricated based on our previous work. A trimming process on silicon channel of FinFET is studied with different time of hydrogen plasma treatements to get a more vertical structure. Results show that subthreshold swing values of all devices are about 65 to 75 mV/dec. Electrical characteristics of device with 300 s trimming are better than those of control one. On the contrary, device with 1200 s trimming show worse performance. Device with 300 s trimming has better performance, demonstarting such as, gate leakage of about 2.94x10-7 A/cm2, transconductance of 32 μA/V and peak carrier mobility of 413 cm2/V-sec. Reliability characteristics of control sample and devices with 300 s trmming are good, showing threshold voltage shift of about 25 mV. Device with 1200 s trimming suffers a much higher threshold voltage shift.
In the second part, in order to continuously promote device characteristics, a high temperature treatment on FinFET is applied to make channel shape smoother. Experimental results show that electrical characteristics are improved with increasing treatment temperature. All samples show subthreshold swing values of about 60 to 70 mV/dec, indicating good gate control capability. Devices with 900℃ treatment have lowest subthreshold swing of 64.3 mV/dec, lowest gate leakage of 3.13x10-8 A/cm2, highest on current of 8.9x10-5 μA/μm, highest transconductance of 114.7μA/V and highest carrier mobility of 488 cm2/V-sec. Moreover, for reliability characteristics, device with 900℃ treatment performs a smaller threshold voltage shift after stressing. The other devices perform higher threshold voltage shifts.
| Identifer | oai:union.ndltd.org:TW/104NTHU5593063 |
| Date | January 2016 |
| Creators | Huang,Tse-Jung, 黃則容 |
| Contributors | Chang-Liao,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 | 80 |
Page generated in 0.0021 seconds