快速寫入金屬閘極非揮發性矽量子點記憶體

Abstract

本論文利用奈秒綠光雷射尖峰退火技術，應用於薄膜電晶體之主動層通道製作及源/汲極退火，以雷射退火技術可使非晶矽薄膜轉換為具1000 nm晶粒之多晶矽薄膜。同時利用化學機械研磨可將其表面平均粗糙度由37A降低為5A，可獲得具超薄(40nm)平坦化之多晶矽薄通道。此外，以雷射退火技術可將離子佈植之多晶矽薄膜做退火，其電阻率小於1 mΩ-cm。結合此低熱預算技術及金屬閘極結構，已成功開發出具有高效能之多晶矽薄膜電晶體，其載子遷移率可高達405 cm2/V-s、次臨界擺幅可低於0.14 V/Decade以及On/Off電流比可超過106。另外，也成功的將低熱預算之多晶矽薄膜電晶體堆疊進行多層堆疊，其各層之電晶體皆展現出相當優異的特性，相當適合應用於三維積體電路元件之發展。另一方面，在低熱預算及高元件性能之基礎下，導入具氧化層/氮化層/矽量子點/氮化層/氧化層之金屬閘極非揮發性記憶體(SiODs-MONOS NVM)，藉由調變穿隧氧化層厚度以及改變阻障氧化層材料，可分別於5V及7V之操作電壓下，快速進行(100ns)進行寫入及抹除，其記憶窗口分別為0.5V及1.2V。因此具低熱預算之金屬閘極薄膜電晶體及非揮發性記憶體皆相當適合應用未來3D-ICs之垂直整合。

In this thesis, the green nanosecond laser spike annealing (GN-LSA) was employed to fabricate the poly-Si channel and source/drain activation of thin film transistor (TFT). The GN-LSA can transfer a-Si into poly-Si with large grain (1000 nm). Moreover, the chemical mechanical polishing (CMP) was used to planarize and thin poly-Si channel that reduces the mean roughness from 37A to 5A and achieve channel thickness to 40 nm. In addition, the GN-LSA reduces the resistivity to 1 mΩ-cm. Combining the thermal budget technologies and metal gate, We have fabricated a high performance TFT that exhibits high electron mobility of 405 cm2/V-s , low subthreshold swing of 0.14 V/Decade, and high on/off ratio of 106. The stacked transistors also reveal the superior electrical characteristic that is suitable for the integration of three-dimensional integrated circuits (3D-ICs). On the basis of low thermal budget technologies and high performance transistor, we introduce a multi-layer of oxide/nitride/SiQDs/nitride/oxide as SiQDs-MONOS nonvolatile memory (SiQDs-MONOS NVM). The SiQDs-MONOS NVM exhibits a fast program/erase speed of 100 ns under 5V and 7V and the memory window is 0.5V and 1.2V by adjusting the thickness of tunneling oxide and varying the material of blocking oxide. Therefore, the TFT and NVMs with metal-gate fabricated by low thermal budget technologies are promising devices for the hetero-integration in 3D-ICs application.