高迁移率In0.6Ga0.4As沟道MOSHEMT与MOSFET器件特性的研究

从模拟和实验两个方面对高迁移率In_0.6Ga_0.4As沟道金属氧化物半导体高电子迁移率晶体管（MOSHEMT）和金属氧化物半导体场效应晶体管（MOSFET）器件开展研究工作.研宄发现InAlAs势垒层对Ino_0.6Ga_0.4AsMOSHEMT的特性具有重要影响.与Ino_0.6Ga_0.4As MOSFET相比,Ino_0.6Ga_0.4As MOSHEMT表现出优异的电学特性.实验结果表明,In_0.6Ga_0.4As MOSHEMT的有效沟道迁移率达到2812 cm²/V.s^-1,是In_0.6Ga_0.4As MOSFET的3.2倍.0.02 mm栅长的MOSHEMT器件较相同栅长的MOSFET器件具有更高的驱动电流、更大的跨导峰值、更大的开关比、更高的击穿电压和更小的亚阈值摆幅.     

N2O处理对背沟刻蚀金属氧化物薄膜晶体管性能的影响

通过采用稀土元素镨掺杂铟锡锌氧化物半导体作为薄膜晶体管沟道层,成功实现了基于铝酸的湿法背沟道刻蚀薄膜晶体管的制备.研究了N₂O等离子体处理对薄膜晶体管背沟道界面的影响,对其处理功率和时间对器件性能的影响做了具体研究.结果表明,在一定的功率和时间处理下能获得良好的器件性能,所制备的器件具有良好的正向偏压热稳定性和光照条件下负向偏压热稳定性.高分辨透射电镜结果显示,该非晶结构的金属氧化物半导体材料可以有效抵抗铝酸的刻蚀,未发现明显的成分偏析现象.进一步的X射线光电能谱测试表明, N₂O等离子体处理能在界面处形成一个富氧、低载流子浓度的界面层.其一方面可以有效抵抗器件在沉积氧化硅钝化层时等离子体对背沟道的损伤;另一方面作为氢的钝化体,抑制了低能级施主态氢的产生,为低成本、高效的薄膜晶体管性能优化方式提供了重要参考.     

Structural properties of Al2O3 dielectrics grown on TiN metal substrates by atomic layer deposition

We investigated on the structural properties of Al₂O₃ dielectrics grown on TiN metal substrates using an atomic layer deposition technique with tri-methyl-aluminum and either O₃ or H₂O as the precursor and oxidant, respectively. The structural and morphological features of these films were examined by atomic force microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy measurements. We find that Al₂O₃ dielectric films with the O₃ oxidant exhibit a rough morphology, a thick TiO₂ film, and a small amount of contaminants such as carbon and hydrogen. The reason for the rapid diffusion of oxygen atoms into the TiN lattice leads to the formation of TiO₂ layer on the TiN substrate. This is due to the higher oxidation potential of the O₃ compared to the H₂O.