碩士 / 國立中山大學 / 光電工程學系研究所 / 103 / Metal-oxide-semiconductor field effect transistors (MOSFETs) play an important role in integrated circuit. The dimension of MOSFETs has been shrinking continuously and follows Moore''s Law. But as MOSFETs is shrunk down into the deep submicrometer dimensions, the gate controllability of the channel potential decreases, resulting in enhanced short channel effect, and also lead to leakage current and realibility issues. Therefore, this thesis will investigate the electrical characteristics and reliability issues in PD-SOI MOSFETs and FinFETs, respectively.
In the first part, the abnormal degradation behavior of body contact (BC) and floating body (FB) operation after hot carrier stress in PD-SOI MOSFETs is investigated. It was found that the hot carrier induced degradation under FB operation is more severe than under BC operation due to the floating body effect. Moreover, it was found that the hot carrier induced degradation under FB operation become insignificant with increasing of temperature. Owing to the difference between forward and reverse drain current(√(I_kink )) was proportional to ∅_B of source/drain PN junction with different temperature can verify that the hot carrier induced degradation under FB operation is dominated by the amount of leaving holes at the source/body PN junction.
In the second part, we investigated an abnormal body current in the linear region in FinFETs. Based on different operation condition, it found that the abnormal body current can be attributed to the leakage current result from the surface defect of fin. Also, the reliability issues of HCS and PBTI were investigated, respectively. It was found that after HCS, the degradation of gate current is more obvious at the source than the drain side. This is because lower energy of channel cold electrons where near the source side is small and leading to the shallow trap in HfO2 layer result in the transmission mechanism of the gate current is dominated by Frenkel-Poole. When measurement by the reverse mode (Source/Drain changed), the electron trapping in the HfO2 layer lead to the transmission mechanism of the gate current is hard to tunneling. Whether forward mode or reverse mode, the transmission mechanism of the gate current after stress was dominated by tunneling, so the rate of tunneling would affect the magnitude of gate current. Therefore, the gate current measured by forward mode is larger than by reverse mode after stress. Moreover, it was found that the transconductance of device with short channel length after PBTI would become better, it can be attributed to the hole trapping in the HfO2 layer and LDD near the source and drain side lead to effective channel length (Leff) is shortened by these accumulated electrons. To further confirmed the origin of the hole trapping phenomenon, simulation of electric field was performed by ISE-TCAD.
| Identifer | oai:union.ndltd.org:TW/103NSYS5124040 |
| Date | January 2015 |
| Creators | Ren-ya Yang, 楊荏雅 |
| Contributors | Ting-Chang Chang, 張鼎張 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 123 |
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