高介电栅介质材料HfO_2掺杂后的物理电学特性(英文)

Physical and electrical properties of the high-κ dielectrics with Ni and Al inclusion in HfO_2

采用激光分子束外延法(LMBE)在p型Si(100)衬底上沉积了(HfO2)x(Al2O3)y(NiO)1-x-y栅介质薄膜,研究了其热稳定性以及阻挡氧扩散的能力。X射线衍射表明在HfO2中掺入Ni和Al元素明显提高了其结晶温度。原子力显微镜测试显示:在N2中退火后薄膜表面是原子级平滑连续的,没有发现针孔。900℃N2中退火后的薄膜在高分辨透射电镜下没有发现硅酸盐界面层。实验结果表明在氧化物薄膜与硅衬底之间引入Ni-Al-O置入层能够防止硅酸盐低介电界面层的生成,这有利于MOS晶体管的进一步尺度缩小。

The thermal stability and the resistance to oxygen diffusion of （HfO2 ）x （Al2O3）y（NiO）1-x-y gate dielectrics deposited on p -type Si （100） substrate by laser molecular beam epitaxy technique （LMBE） have been investigated. X- ray diffraction （XRD） results indicate that the crystallization temperature significantly increases with Ni and Al added into the HfO2 film. Atomic force microscopy （AFM） testing shows that the surface of these films after annealing in N2 is continuous and flat at the atomic level with no pinhole observed. No silicate interracial layer is found in the high -resolution cross -section transmission electron microscope （HRTEM） images of the （ HfO2 ） x （ Al2O3 ） y （NiO）1 -x - y films after 900℃ annealing in N2. It is indicated that the interposed layer of Ni - Al - O between the oxide film and the Si substrate enables to avoid the formation of low -κ silicate interfaeial layer, which is favorable for MOS to further downscale.