Si83Ge17／Si压应变衬底上HfO2栅介质薄膜的电学性能

本文用射频磁控溅射方法在p-si83Ge17／Si压应变衬底上沉积制备Hf02栅介质薄膜，研究其后退火处理前后的电学性能，并与相同条件沉积在无应变p-Si衬底上Hf02薄膜的电学性能进行对比研究．物性测试分析结果表明，沉积Hf02薄膜为单斜相（m-Hf02）多晶薄膜，薄膜介电常数的频率依赖性较小，1MHz时薄膜介电常数k约为23．8．在相同的优化制备条件下，沉积在si83Ge17／si衬底上的Hf02薄膜电学性能明显优于沉积在Si衬底上的薄膜样品：薄膜累积态电容增加；平带电压‰骤减至-0．06V；电容．电压滞后回线明显减小；-1V栅电压下漏电流密度，减小至2．51 x 10-5A·cm-2．实验对比结果表明Si83Ge17应变层能有效地抑制Hf02与si之间的界面反应，改善HfO2／Si界面性质，从而提高薄膜的电学性能．

Dielectric properties of HfO2 films deposited on compressively strained SisaGel7/Si substrate by sputtering

Dielectric properties of HfO2 films deposited on compressively strained Si83GelT/Si substrate by using radiofrequency magnetron sputtering have been investigated. It is demonstrated that the as-deposited HfO2 films has monoclinic crystalline structure and the measured permittivity shows no remarkable frequency dependence （-23.8 at 1 MHz）. Comparison experiment reveals that under the same optimized conditions （room temperature growth in 3 Pa Ar ambient with working power of 70 W and thermal annealing treatment in N2 atmosphere at 350~C for 30 min）, dielectric properties of the HfO2 films on Si83Ge17/Si（100） substrate are better than that on Si（100） substrate, such as relatively large accumulation capacitance, low leakage current density （2.51x10-5 A.cm-2 at -1 V gate voltage）, lowe flat band voltage （-0.06 V）, and smaller hysteresis of capacitancevoltage curves. It is argued that compressively strained Si83Ge17 buffer layer depresses interfacial reaction between HfO2 and Si, and results in improved dielectric properties of the HfO2 films on SilaGe, 7/Si substrate.