Determination of Energy Distribution of Defect State Density for Ultrathin SiO_2/Si Interfaces by Using Photoelectron Yield Spectroscopy

光电子能谱测定超薄SiO_2/Si界面缺陷态密度能量分布

• 批准号: 08455147
• 负责人: MIYAZAKI Seiichi
• 金额: $ 4.35万
• 依托单位: HIROSHIMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08455147/
• 关键词: Ultrathin SiO_2; c-Si Interface; Photoelectron Yield Spectroscopy; Sur11face Fermi Level; Surface States Density; Valence Band State Density; Photoelectron Escape Depth; Interface State Density; Hydrogen Terminated Si Surface; 欠陥準位密度; ケルビンプローブ /

A system for total photoelectron yield spectroscopy (PYS) with a high sensitivity has been developed to determine the energy distribution of gap state densities for H-terminated c-Si surfaces and thermally-grown SiO_2/c-Si interfaces. The PYS system was installed in an UHV chamber for X-ray/ultraviolet excited photoelectron spectroscopy together with a Kelvin probe, which enables us to determine Fermi energy on a sample surface with an accuracy of a few meV.1. In the PYS system, a dynamic range of eight orders of magnitude was obtained for c-Si and SiO_2/c-Si samples.2. The threshold energies for direct and indirect photoexitations are determined by liner and cubic root plots of PYS spectra for the samples. This leads us to determine the energy position of the valence band edge on the surface independent of the amount of surface band bending.3. On the basis of the density of states near the valence band edge obtained from the XPS valence band spectrum for c-Si, the gap state density as low as 10^<10>cm^<-2>eV^<-1> can be detected and determined from the first derivative PYS spectrum.4. The escape depth for 5.6 eV-excited photoelectrons in SiO_2 was estimated to be 3.1nm from the yield reduction rate for the SiO_2/c-Si system.5. There exist interface states around midgap with densities as high as -10^<12>cm^<-2>eV^<-1> in an as-grown 2.7nm-thick SiO_2/n^+Si interface. 400ﾟC annealing in an H_2 + N_2 gas mixture reduces the interface state density by one order of magnitude for the sample without any gate metal.

已经开发了具有高灵敏度的总光电产率光谱（PYS）的系统，以确定H端态的C-SI表面和热生长的SIO_2/C-SI接口的间隙状态密度的能量分布。 PYS系统安装在UHV室中，用于X射线/紫外线激发光电子光谱以及开尔文探针，这使我们能够在样品表面上确定Fermi Energy的精度，并准确地确定了一些MEV.1。在PYS系统中，对于C-SI和SIO_2/C-SI样品，获得了八个数量级的动态范围。2。直接和间接光检查的阈值能由样品的PYS光谱的衬里和立方根图确定。这导致我们确定表面上价带边缘的能量位置，而不是表面带弯曲的量。3。基于从XPS价带光谱获得的c-Si的价值带边缘附近的状态密度，可以从第一个衍生Pys Pys Spectrum.4中检测并确定间隙状态密度低至10^<10> cm^<-2> ev^<-1>。 SIO_2中5.6 EV激发光电子的逃生深度估计为SIO_2/C-SI系统的降低率为3.1nm.5。在MidGap周围存在的接口状态，密度高达-10^<12> CM^<-2> EV^<-1>在2.7nm-Thick Sio_2/n^+Si接口中。在H_2 + N_2气体混合物中进行400°C退火可将界面状态密度降低一个没有任何栅极金属的样品的数量级。

项目成果

S.Miyazaki: "Evaluation of Gap States in Hydrogen-Terminated Silicon Surfaces and Ultrathin SiO_2/Si Interfaces by Using Photoelectron Yield Spectroscopy" Mat.Res.Soc.Symp.Proc.500 (to be published). (1998)

S.Miyazaki：“使用光电子产率光谱法评估氢端硅表面和超薄 SiO_2/Si 界面中的间隙态”Mat.Res.Soc.Symp.Proc.500（待出版）。

S.Miyazaki: "Implication of Hydrogen-Induced Boron Passivation in Wet-Chemically Cleaned Si (111) : H" Applied Surface Science. 117/118. 32-35 (1997)

S.Miyazaki：“氢致硼钝化对湿式化学清洁的 Si (111) 的影响：H”应用表面科学。

D.Imafuku: "Organic Contamination of Silicon Wafers in Clean Room Air and Its Impact to Gate Oxide Integrity" Mat.Res.Symp.Proc.477. 101-105 (1997)

D.Imafuku：“洁净室空气中硅片的有机污染及其对栅极氧化物完整性的影响”Mat.Res.Symp.Proc.477。

S.Miyazaki: "Electronic States of Hydrogen-Terminated Silicon Surfaces and SiO_2/Si Interfaces" Proc.of JRCAT Intern. Workshop on Sci.and Technol.of Hydrogen-Terminated Silicon Surfaces. 35-36 (1997)

S.Miyazaki：“氢封端硅表面和 SiO_2/Si 界面的电子态”Proc.of JRCAT Intern。

Seiichi Miyazaki: "Structure and Electronic States of Ultrathin SiO_2 Thermally Grown on Si (100) and Si (111) Surfaces" Appl. Surf. Sci.(1997)

Seiichi Miyazaki：“在Si（100）和Si（111）表面上热生长的超薄SiO_2的结构和电子态”Appl。