化學機械研磨技術和N2O退火對複晶矽氧化層特性之影響

Abstract

在本論文中,我們利用化學機械研磨技術和高溫退火處理來改善化學氣相沈積複晶矽氧化層(LPCVD TEOS)氧化層的特性.複晶矽氧化層的特性跟複晶矽氧化層與複晶矽介面有相當大的關係,而複晶矽表面經過化學機械研磨技術處理後可以得到較平坦的表面.更進一步來說,以化學氣相沈積複晶矽氧化層(LPCVD TEOS)可以有比熱成長氧化層平坦的介面,而在高溫退火之後更可以得到極佳的特性.結合化學機械研磨技術和快速加熱退火可以使複晶矽氧化層得到極佳的J-E特性曲線和較大的崩潰電荷及降低電子補抓率. 此外我們還討論了各種溫度的N2O退火對複晶矽氧化層特性的影響,我們發現在正崩潰電荷上850℃有較佳的特性,但在愈高溫時複晶矽氧化層卻有愈大的負崩潰電荷.

In this thesis, the integrity of TEOS polyoxide with Chemical Mechanical Polishing process and a high temperature annealing has been studied. The integrity of polysilicon oxide heavily depends on the surface morphology of polysilicon-oxide/polysilicon interface and the oxidants that were used for growth or post-oxidation annealing. The surface morphology of polysilicon is improved after a CMP process. The polyoxide deposited by TEOS vapor have a smoother surface and better electric characteristics after high temperature annealing. In the study, polyoxides deposited by LPCVD TEOS with combination of CMP and RTA would obtain preferable J-E curve and higher charge to breakdown and lower electron trapping rate. Moreover, we discuss the characteristics of TEOS polyoxide annealed in N2O at different temperature. For +Vg injection, the polyoxide annealed in N2O at 850℃ has fewer electron trapped and higher charge-to-breakdown than others. However, for –Vg injection the polyoxide annealed in N2O at 1050℃ has the fewest electron trapped and highest charge-to-breakdown.