利用伸張形變下之溫度處理改善乾氧生長氧化層之金氧半電容元件特性

Quality Improvement of MOS Capacitors with Oxides Growth in Dry O2 by External Tensile-Temperature Stress Treatment

龔鍵(Chien Kung)

指導教授 ： 胡振國

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.00061

摘要

金氧半結構是一種存在於CMOS(互補式金氧半導體)製程中的基本的型式。自從金氧半導體場效電晶體被發明以來，二氧化矽巳經被用作為其閘極氧化層超過四十年之久，因為二氧化矽擁有極佳的穩定性和均勻度且製作過程較為簡單。根據以上的敘述，為了更深入的了解金氧半電容的效應，因此有兩個問題需要被考慮，其中一個問題是熱效應對於元件特性表現上的影響，另一個則是晶圓切割所造成的影響。
在本篇文章中，應力對於二氧化矽氧化層所造成的影響將會被探討，關於熱應力的影響關連性及金氧半電容的特性也同時會被討論。而在此次的工作中，也展示出藉由外加的拉伸溫度應力造成金氧半電容元件在電性特性上不同的表現結果。
在第二章中，為了研究熱效應所造成的影響，我們將金氧半電容元件放置於100℃的烤箱內達10分鐘且持續兩次，並同時施予外加的應力(拉伸基板)來觀察其變化。藉由量測界面陷阱密度和電流變化程度來比較其電性特性，經由實驗的結果發現經過拉伸溫度施壓(tensile-temperature stress)後，可以呈現出最好的氧化層特性。
在第三章中，TZDB (Time zero dielectric breakdown)的穩定度表現將會被探討，同時我們也展示了經由外加的拉伸溫度施壓後，可以造成TZDB穩定度的改善，但在連續的兩次施壓下，也發現到TZDB穩定度的表現在不同的次數下會有不同的結果。觀察以上的實驗結果，也發現到TZDB穩定度的改善可能只是屬於暫時性的改變，並不是永久性的。

關鍵字

金氧半元件

並列摘要

The metal-oxide-semiconductor (MOS) structure is the basis work for the complementary metal-oxide-semiconductor (CMOS) technology. Silicon oxide has been used as a gate dielectric of MOSFETs for more than forty years since MOSFET had been introduced due to its excellent stability, uniformity, and easy fabrication process. As above descriptions, in order to understand the effect of MOS capacitor, two issues should be considered. One is the thermal effect on device performance and the other is the influence of wafer sawing.
In the thesis, the effects of mechanical stress on silicon oxidation were studied only. The relation of thermal stress and the electrical characteristics of MOS capacitor are investigated. This study is a pioneering work on the subject since mechanical stress problems are considered to be one of the most important issues in the next generation of integrated circuit technology. Our works have demonstrated the substantial effects of tensile-temperature stress caused by the external adapted on the electrical characteristics of oxides.
In chapter 2, we investigated the thermal effect for MOS capacitors after receiving thermal treatment at 100℃ for 10minutes with external mechanical stresses applied on the substrate. And the measurement of interface traps density and current variation were made to compare the electrical characteristics of MOS capacitors. The experimental result shows tensile-temperature stress exhibits the best properties of interface traps density and I-V curve.
In chapter 3, the TZDB reliability was studied. We have demonstrated that the external tensile-temperature stress can result in TDZB reliability improvement. After two times of tensile-temperature stress performed, we found the result of TZDB reliability has a little different. As above description, we wonder that the effect of tensile-temperature stress is temporary for the TZDB reliability improvement, but not permanent

並列關鍵字

MOS Capacitor ； Tensile

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