摻雜濃度與沈積後處理對複晶矽氧化層的影響

Abstract

在此論文中，我們完整地探討O2與N2O成長之複晶矽氧化層的最佳化複晶矽摻雜濃度，我們亦研究了不同的氧化製程(O2與N2O的熱氧化成長以及TEOS 化學氣相沉積)與不同的沉積後處理(爐管熱退火、快速熱退火、ECR電漿處理)對複晶氧化層電性的影響。 研究結果顯示，以N2O成長的複晶矽氧化層其底電極片電阻在50歐姆/y 左右有較低的漏電流、較高的崩潰電壓、以及較大的崩潰電荷。 其次，經由快速熱退火製程N2O氮化後的薄TEOS氧化層，在電性的表現上有非常顯著的改善。這是由於在氮化過程中會減少氧化層缺陷並會在TEOS氧化層與複晶矽界面間形成一層薄氧氮化矽的原故。再則，複晶矽氧化層經由ECR電漿處理亦得到不錯的效果，其原因相信為高活性離子(radicals)會修補缺陷並改善氧化層的品質，並且在複晶矽氧化層中有較低的氫濃度會降低載子的捕捉。

In this thesis, we performed a systematic study of the optimization of the bottom polysilicon doping level for the O2- and N2O-grown polyoxide. We also presented the electrical characteristics of the polyoxides using different oxidation processes (O2 and N2O thermal oxidation and TEOS LPCVD) and different post-deposition annealing (Furnace thermal annealing, rapid thermal annealing, and ECR plasma treatment) on TEOS deposited oxide. The results show that the bottom polysilicon with sheet resistance about 50Ω/sq of N2O-grown polyoxide had a lower leakage current, higher breakdown field and larger charge to breakdown. Besides, the RTN2O-annealed thin CVD TEOS polyoxide had much-improved characteristics due to low defects and interfacial oxynitride. Finally, polyoxides with ECR plasma treatment also exhibit desirable electrical characteristics. It is believed that the highly reactive radicals can repair the defects and improve oxide quality. Moreover, the less hydrogen incorporation in polyoxide was observed in SIMS profile to reduce the H-related carrier traps.