使用氧化鋯及氧化鑭薄膜之電容器與場效電晶體的電性與可靠度分析

The Electrical and Reliability Properties of Metal-Insulator-Silicon Capacitors and Field-effect Transistors with ZrO2 and La2O3 Gate Dielectrics

徐德誠(De-Cheng Hsu)

指導教授 ： 李雅明

國立清華大學/電機資訊學院/電子工程研究所/碩士(2006年)

摘要

無資料

關鍵字

高介電材料, 依時性介電崩潰, 氧化鋯, 氧化鑭

並列摘要

Metal-insulator-semiconductor (MIS) capacitors and n-channel field effect transistors with ZrO2 and La2O3 gate dielectrics were successfully fabricated. The reliability issues such as time dependent dielectric breakdown (TDDB) and static positive bias temperature instability (PBTI) have been discussed. In the TDDB section, the Weibull slope and area scaling factors of ZrO2 gate dielectric have been investigated. The extracted Weibull slope (β) for different thickness of 20 nm and 7.5 nm is found to be 1.4 and 1.1, respectively. The TDDB data are better described by the E-model. The maximum operation voltage range for ten-year lifetime of capacitors with an area of 3.14x10-4cm2 and thickness of 20 nm was projected to be about -2.3V to -0.8V in the temperature range from 25 to 150 ℃. The relation of activation energy (Ea) and oxide field (Eox) is given by Ea = -1.04 Eox+0.773. The field acceleration factor (γ) is shown to be independent with temperature in our study.
The PBTI characteristics of NMOSFETs with ZrO2 and La2O3 gate dielectrics have been examined. Both oxide-trapped and interface-trapped charges can contribute to threshold voltage (Vt) shift. The Vt degradation of ZrO2-gated MOSFETs is mainly caused by interface-trap charges, but that for La2O3-gated MOSFETs is mainly caused by oxide-trapped charges. This trend is found to be true at temperatures 25 and 75℃. The Vt shifts negatively and Vt degradation versus time follows a power law relation.

並列關鍵字

high-k, time-dependent-dielectric breakdown(TDDB), bias temperature instability, PBTI, ZrO2, La2O3

參考文獻

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