原子層沉積技術製作氧化鋁膜於薄膜電晶體之應用

Atomic Layer Deposited Al2O3 for Thin Film Transistor Applications

洪瑞華(Ray-Hua Horng) ； 吳秉叡(Bing-Rui Wu) ； 賴宜楓(Yi-Feng Lai) ； 武東星(Dong-Sing Wuu)

《真空科技》 26卷1期 (2013/03) Pp. 34-44

摘要

Atomic layer deposition (ALD) is a novel thin film technology with a highly competitive for semiconductor fabrication. The advantages of ALD are that it is a low temperature thin film technique, has no plasma damage, no gas-phase reaction, and high precursor utilization. Because of its self-limiting surface chemistry reaction, ALD usually offers a precise control in the film thickness and composition with almost excellent uniformity and step coverage. ALD is applied for fabricating high permittivity gate insulator (GI), such as Al2O3, for thin film transistors due to its benefits. In this study, thin film transistors have been fabricated low temperature (＜400°C) Al2O3 as a GI-layer material grown by ALD.For Al2O3 deposition, ALD was carried out by repeating the cycle of trimethylaluminum (Al(CH3)3, TMA) adsorption and oxidation by pure water (H2O) at 100°C and 300°C. In order to better understand the quality of deposited Al2O3, samples are characteristic by n & k analyzer, atomic force microscopy (AFM), water vapor transmission rates (WVTR), and scanning electron microscopy (SEM).After characterization, good step coverage of ALD is observed by SEM cross-section image for Al2O3 films deposited at 100°C. AFM images reveal well surface roughness for samples with different process cycles from 200 to 1000 cycles. Finally, our TFT device containing ALD deposited Al2O3 GI-layer is operated with a threshold voltage and on/off ratio of 10V and 200, respectively. Furthermore, the saturation mobility is ~ 2.3 cm^2/V·s in this device.

關鍵字

氧化鋁 ； 原子層沉積 ； 薄膜電晶體 ； 閘極介電層

並列摘要

Atomic layer deposition (ALD) is a novel thin film technology with a highly competitive for semiconductor fabrication. The advantages of ALD are that it is a low temperature thin film technique, has no plasma damage, no gas-phase reaction, and high precursor utilization. Because of its self-limiting surface chemistry reaction, ALD usually offers a precise control in the film thickness and composition with almost excellent uniformity and step coverage. ALD is applied for fabricating high permittivity gate insulator (GI), such as Al2O3, for thin film transistors due to its benefits. In this study, thin film transistors have been fabricated low temperature (＜400°C) Al2O3 as a GI-layer material grown by ALD.For Al2O3 deposition, ALD was carried out by repeating the cycle of trimethylaluminum (Al(CH3)3, TMA) adsorption and oxidation by pure water (H2O) at 100°C and 300°C. In order to better understand the quality of deposited Al2O3, samples are characteristic by n & k analyzer, atomic force microscopy (AFM), water vapor transmission rates (WVTR), and scanning electron microscopy (SEM).After characterization, good step coverage of ALD is observed by SEM cross-section image for Al2O3 films deposited at 100°C. AFM images reveal well surface roughness for samples with different process cycles from 200 to 1000 cycles. Finally, our TFT device containing ALD deposited Al2O3 GI-layer is operated with a threshold voltage and on/off ratio of 10V and 200, respectively. Furthermore, the saturation mobility is ~ 2.3 cm^2/V·s in this device.

並列關鍵字

Aluminum Oxide ； Atomic Layer Deposition ； Thin Film Transistors ； Gate Insulator