硅表面清洗对热氧化13nm SiO_2可靠性的影响  

Effect of Silicon Surface Cleaning on Reliability of 13nm Gate Oxide

作　　者：高文钰[1] 刘忠立[1] 和致经[1] 于芳[1] 梁桂荣[1] 李国花[1] 

机构地区：[1]中国科学院半导体研究所

出　　处：《Journal of Semiconductors》1999年第5期383-388,共6页半导体学报（英文版）

基　　金：国家自然科学基金

摘　　要：实验研究表明热生长１３ｎｍ薄ＳｉＯ２的可靠性同氧化前硅表面清洗处理方法有很大关系．氧化前稀ＨＦ酸及ＨＦ／乙醇漂洗不会提高热氧化薄ＳｉＯ２的可靠性；氧化前用ＮＨ４ＯＨ／Ｈ２Ｏ２／Ｈ２Ｏ（０．０５∶２∶５）溶液清洗形成化学预氧化层对提高薄ＳｉＯ２可靠性很有效；用Ｈ２ＳＯ４／Ｈ２Ｏ２（３∶１）溶液清洗形成预氧化层的改善作用也较明显，在之前增加比例为０．０５∶２∶５或１∶２∶５的ＮＨ４ＯＨ／Ｈ２Ｏ２／Ｈ２Ｏ溶液清洗和稀ＨＦ酸漂洗效果更好．另外，薄栅介质抗电离辐射性能和抗热电子损伤能力同氧化前形成化学预氧化层的清洗液种类关系不大，电离辐射对薄栅介质击穿特性的影响不明显．Abstract This paper shows that silicon surface cleaning has great effect on the reliability of 13nm gate oxides. It is demonstrated that dipping in diluted HF or HF/Ethanol solution prior to thermal oxidation leads to poor breakdown strength and large variation of the breakdown strength for the thin gate oxides. Chemical preoxide formation in NH 4OH /H 2O 2 /H 2O (0 05∶2∶5) solution prior to thermal oxidation is shown to be an effective way to get 13nm thermal oxide with high integrity. Chemical preoxide formed in H 2SO 4 /H 2O 2 (3/1) solution can also improve the reliability of thin thermal oxides, and the improvement is enhanced by adding NH 4OH/H 2O 2 /H 2O (0 05∶ 2∶5 or 1∶2∶5) cleaning and diluted HF dipping before the H 2SO 4/H 2O 2 clean step. It is also shown that the immunity against ionizing radiation or hot carrier damage of the thin gate oxides does not have much relationship with the type of the chemical solutions in which the preoxides are formed. In addition, ionizing irradiation does not clearly change the breakdown properties of the thin gate oxides.

关 键 词：硅 二氧化硅 热氧化 表面清洗 可靠性 

分 类 号：TN304.21[电子电信—物理电子学] TN305.2