Improvement of Device Characteristics for TiN Gate p-Type Metal–Insulator–Semiconductor Field-Effect Transistor with Al2O3-Capped HfO2 Dielectrics by Controlling Al2O3 Diffusion Annealing Process
Improvement of Device Characteristics for TiN Gate p-Type Metal–Insulator–Semiconductor Field-Effect Transistor with Al2O3-Capped HfO2 Dielectrics by Controlling Al2O3 Diffusion Annealing Process
复制标题
通过控制 Al2O3 扩散退火工艺改善具有 Al2O3 覆盖 HfO2 电介质的 TiN 栅极 p 型金属绝缘体半导体场效应晶体管的器件特性
DOI：
10.1143/jjap.48.04c010
复制
发表时间：
2009
影响因子：
1.5
通讯作者：
Y. Ohji
中科院分区：
文献类型：
--
作者：
T. Morooka;T. Matsuki;N. Mise;S. Kamiyama;T. Nabatame;T. Eimori;Y. Nara;Y. Ohji
我们研究了 Al2O3 覆盖的 HfO2 薄膜的沉积后退火 (PDA) 对 TiN 栅极 p 型金属绝缘体半导体场效应晶体管 (pMISFET) 平带电压 (Vfb) 漂移和阈值电压 (Vt) 变化的影响。我们发现优化 PDA 条件以将 Al2O3 扩散到 HfO2 薄膜中是控制 Vfb 的关键因素，并且在 Al2O3 沉积后立即进行高温 PDA 会引起正 Vfb 偏移。当 Al2O3 沉积后 PDA 温度为 850 和 950 °C 时，观察到额外的 Vt 变化。相比之下，Al2O3 沉积后 1050 °C 的较高温度 PDA 可以将 Vt 变化抑制到几乎与没有 Al2O3 盖层的 HfO2 薄膜中获得的水平相同的水平，尽管等效氧化物厚度 (EOT) 增加。我们还发现，通过在 Al2O3 沉积之前进行 PDA，可以获得优异的器件特性，例如低 Vt、抑制 Vt 变化和抑制 EOT 增加。
We have investigated the effect of postdeposition annealing (PDA) of Al2O3-capped HfO2 films on the flatband voltage (Vfb) shift and threshold voltage (Vt) variation in TiN gate p-type metal–insulator–semiconductor field-effect transistors (pMISFETs). We found that optimizing the PDA conditions to diffuse Al2O3 into the HfO2 films is a key factor for controlling Vfb, and high-temperature PDA immediately after Al2O3 deposition induces a positive Vfb shift. Additional Vt variation was observed when the PDA temperatures after Al2O3 deposition were 850 and 950 °C. In contrast, a higher temperature PDA at 1050 °C after Al2O3 deposition can suppress Vt variation to almost the same level as that obtained in a HfO2 film without an Al2O3-cap layer, although the equivalent oxide thickness (EOT) increases. We also found that superior device characteristics, such as low Vt, suppression of Vt variation, and suppression of EOT increase, were obtained by performing PDA before Al2O3 deposition.