研究生: |
呂榮哲 Lyu, Rong-Jhe |
---|---|
論文名稱: |
結晶態高介電常數材料結合稀土族氧化物介面層作為金氧半電容元件閘極堆疊結構之研究 Study of Crystalline High-K Materials Combined with Rare-Earth Oxide Interfacial Layer as the Gate Stack for MOS Devices |
指導教授: |
巫勇賢
Wu, Yung-Hsien |
口試委員: |
巫勇賢
吳永俊 高瑄苓 |
學位類別: |
碩士 Master |
系所名稱: |
原子科學院 - 工程與系統科學系 Department of Engineering and System Science |
論文出版年: | 2011 |
畢業學年度: | 99 |
語文別: | 中文 |
論文頁數: | 82 |
中文關鍵詞: | 結晶 、高介電常數材料 、稀土族 、介面層 、金屬-氧化物-半導體 、電容 |
相關次數: | 點閱:3 下載:0 |
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為了迎合當前CMOS元件的發展方向,本研究之目的在於微縮半導體電容元件閘極氧化層之等效氧化厚度,並在微縮的同時達到良好的元件特性。因此本研究中,我們同時將結晶態高介電材料與稀土族氧化物介面層之堆疊結構應用於矽基板上以及鍺基板上,來達到兩種半導體基板上等效氧化層微縮並兼顧良好之介面特性。
在第一個研究主題,我們製作了ZrO2/Y2O3與ZGZ/Y2O3兩種堆疊結構作為之鍺電容元件。物性分析中,我們証實ZGZ夾層的確形成結晶態Tetragonal ZrO2,以及Y2O3介面層與鍺基板之間具有良好的介面品質。電性量測方面,ZGZ/ Y2O3結構之元件比起ZrO2/Y2O3結構之元件具有較大的電容值以及較小並接近1nm的等效氧化層厚度。在漏電流表現上,ZGZ/Y2O3結構之元件具有較大的電流,但是由於有Y2O3材料存在,元件皆表現了相當低的漏電流。最後,介面缺陷密度數值顯示,兩元件具有約略相同而且低的介面缺陷密度,證明Y2O3材料作為鍺基板元件介面層之可行性。
在第二個研究主題,在第一部份我們先製作了Al/Yb2O3/Si電容元件。從Al/ Yb2O3/Si電容元件之電性結果顯示,使用700oC熱處理之Yb2O3薄膜其元件具有最佳之電性。因此我們根據第一部分的結果以700oC熱處理之Yb2O3薄膜作為介面層接著製作了TaN/ ZrTiO4/Yb2O3/Si電容元件,並分成沒有經過RTA以及有經過800oC RTA之元件。物性分析顯示,有經過800oC RTA的元件形成結晶態Orthorhombic ZrTiO4,並證實Yb金屬矽氧化物的存在。電性量測方面,有經過800oC RTA之元件比起沒有經過RTA之元件具有較大的電容值以及小於1nm的等效氧化層厚度。在漏電流表現上,有經過800oC RTA之元件具有較大的電流,但是由於Yb2O3此具有相當大導電帶能帶偏移量之介面層存在,元件皆表現了相當低的漏電流。接著,進一步的可靠度量測中顯示,有經過800oC RTA之元件具有較差的NBTI以及SILC表現。不過若以等效電場的角度來看待量測結果,則有經過800oC RTA之元件因其具有相當低的等效氧化層厚度,使其在各項電性上表現常能夠超越沒有經過RTA之元件。
總和以上結果,我們發現使用結晶態高介電常數材料作為閘極氧化層材料能夠在較夠的物理厚度下輕易微縮等效氧化層厚度到達1nm左右。此外,若結合稀土族氧化物介面層形成堆疊結構,更能夠擁有低的漏電流數值,並表現出不錯的介面缺陷密度以及良好可靠度。因此我們認為,此結晶態高介電常數材料結合稀土族氧化物介面層之堆疊結構作為CMOS元件之閘極氧化層取代材料而言具有相當大的潛力。
第一章
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第二章
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第三章
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structure of ZrTiO4 and HfTiO4: Self-consistent
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2011