共查询到14条相似文献,搜索用时 0 毫秒
1.
A new ternary rare oxide dielectric LaYbO3 film had been prepared on silicon wafers and quartz substrates by reactive sputtering method using a La-Yb metal target. A range of analysis techniques was performed to determine the optical band gap, thermal stability, and electrical property of the deposited samples. It was found the band gap of LaYbO3 film was about 5.8 eV. And the crystallization temperature for rapid thermal annealing (20 s) was between 900 and 950 °C. X-ray photoelectron spectroscopy results indicate the formation of the SiO2 and silicate in the interface between silicon wafer and LaYbO3 film. The dielectric constant is about 23 from the calculation of capacitance-voltage curve, which is comparable higher than previously reported La2O3 or Yb2O3 film. 相似文献
2.
In this article, the authors developed a high-k HoTiO3 gate dielectric deposited on Si (1 0 0) through reactive cosputtering. They found that the HoTiO3 dielectrics annealed at 800 °C exhibited excellent electrical properties such as high capacitance value, small density of interface state, almost no hysteresis voltage, and low leakage current. This phenomenon is attributed to the decrease in intrinsic defect (related to oxygen vacancy) due to a rather well-crystallized HoTiO3 structure and composition observed by X-ray diffraction, secondary ion mass spectrometry, and X-ray photoelectron spectroscopy, respectively. 相似文献
3.
In this work, we report on two properties of the oxidation of tantalum silicide (Ta2Si) on SiC substrates making this material of interest as insulator for many wide bandgap or compound semiconductors. The relatively high oxidation rate of tantalum silicide to form high-k insulator layers and its ability for being oxidized in diluted N2O ambient in a manner similar to the oxidation in O2 are investigated. Metal-insulator-semiconductor capacitors have been used to establish the actual applicability and constrain of the high-k insulator depending on the oxidation conditions. At 1050 °C, the reduction of the oxidation time from 1 h to 5 min affects primordially the SiOx interfacial layer formed between the bulk insulator and the substrate. This interfacial layer strongly influences the metal-insulator-semiconductor performances of the oxidized Ta2Si layer. The bulk insulator basically remains unaffected although some structural differences arise when the oxidation is performed in N2O. 相似文献
4.
M. Caymax M. Houssa G. Pourtois F. Bellenger K. Martens A. Delabie S. Van Elshocht 《Applied Surface Science》2008,254(19):6094-6099
Important progress has been made in the passivation of Ge/gate dielectric interfaces. One important approach is by thermally oxidized GeO2 interface and ALD high-k layers, with an interface state density Dit ∼ 2 × 1011 cm−2 eV−1. Another approach is with an epi-Si/SiO2 interface, resulting in similar Dit. Hysteresis and Vth shift, however, are still not optimal. Extensive material characterization and theoretical insights help us understanding the root cause of these remaining issues and show the way to improved interface control. 相似文献
5.
High-k ytterbium oxide (Yb2O3) gate dielectrics were deposited on Si substrate by reactive sputtering. The structural features of these films after postdeposition annealing treatment were studied by X-ray diffraction and X-ray photoelectron spectroscopy. It is found that the Yb2O3 gate dielectrics annealed at 700 °C exhibit a larger capacitance value, a lower frequency dispersion and a smaller hysteresis voltage in C-V curves compared with other annealing temperatures. They also show negligible charge trapping under high constant voltage stress. This phenomenon is mainly attributed to the decrease in the amorphous silica thickness. 相似文献
6.
R. Yasuhara H. Kumigashira M. Oshima F. Guo T. Kinoshita K. Ono K. Ikeda Z. Liu 《Applied Surface Science》2008,254(15):4757-4761
We have applied the spectroscopic photoemission and low energy electron microscope to study high-k gate dielectrics and have performed the following in situ operations during ultrahigh vacuum annealing: real-time observation of surface morphology and microregion photoelectron spectroscopy measurements. Changes in surface morphology and electronic states were consistent with the models previously reported in the case of HfO2/Si. No clear differences between void regions and nonvoid regions have been observed in microregion photoelectron spectra for poly-Si/HfO2/Si, regardless of phase separation in real space. These results have suggested that the initial void formation occurs in about 100-nm wide regions for both HfO2/Si and poly-Si/HfO2/Si. 相似文献
7.
The remote plasma nitridation (RPN) of an HfO2 film using N2 and NH3 has been investigated comparatively. X-ray photoelectron spectroscopy and Auger electron spectroscopy analyses after post-deposition annealing (PDA) at 700 °C show that a large amount of nitrogen is present in the bulk film as well as in the interfacial layer for the HfO2 film nitrided with NH3-RPN. It is also shown that the interfacial layer formed during RPN and PDA is a nitrogen-rich Hf-silicate. The C-V characteristics of an HfOxNy gate dielectric nitrided with NH3-RPN have a smaller equivalent oxide thickness than that nitrided with N2-RPN in spite of its thicker interfacial layer. 相似文献
8.
Large scale ab initio molecular dynamics simulations were performed to investigate how Cu/ultra low-k systems are improved when N is incorporated into the pore-sealing layers. It was found that the high affinity of N to Ta and H gives rise to new phases that prevent H atoms from penetrating the Ta diffusion barrier layer. Consequently, the Ta layer forms organized structures with good barrier performance and electrical conductivity. Furthermore, a continuous ductile film is formed to seal the highly porous polymer dielectrics. Interfacial adhesion between the pore-sealing layer and the dielectrics is also enhanced by inter-diffusion. 相似文献
9.
An understanding of the exact structural makeup of dielectric interface is crucial for development of novel gate materials. In this paper a study of the HfO2/Si interface created by the low-temperature deposition ultrathin stoichiometric HfO2 on Si substrates by reactive sputtering is presented. Analysis, quantification and calculation of layer thickness of an HfO2/Hf-Si-Ox/SiO2 gate stack dielectrics have been performed, using X-ray photoelectron spectroscopy (XPS) depth profile method, angle resolved XPS and interface modeling by XPS data processing software. The results obtained were found to be in good agreement with the high frequency capacitance-voltage (C-V) measurements. The results suggest a development of a complex three layer dielectric stack, including hafnium dioxide layer, a narrow interface of hafnium silicate and broad region of oxygen diffusion into silicon wafer. The diffusion of oxygen was found particularly detrimental to the electrical properties of the stack, as this oxygen concentration gradient leads to the formation of suboxides of silicon with a lower permittivity, κ. 相似文献
10.
S. Abermann C. Henkel O. Bethge G. Pozzovivo P. Klang E. Bertagnolli 《Applied Surface Science》2010,256(16):5031-5034
The impact of the ZrO2/La2O3 film thickness ratio and the post deposition annealing in the temperature range between 400 °C and 600 °C on the electrical properties of ultrathin ZrO2/La2O3 high-k dielectrics grown by atomic layer deposition on (1 0 0) germanium is investigated. As-deposited stacks have a relative dielectric constant of 24 which is increased to a value of 35 after annealing at 500 °C due to the stabilization of tetragonal/cubic ZrO2 phases. This effect depends on the absolute thickness of ZrO2 within the dielectric stack and is limited due to possible interfacial reactions at the oxide/Ge interface. We show that adequate processing leads to very high-k dielectrics with EOT values below 1 nm, leakage current densities in the range of 0.01 A/cm2, and interface trap densities in the range of 2-5 × 1012 eV−1 cm−2. 相似文献
11.
A.J. Conley W.D. Collins 《Journal of Quantitative Spectroscopy & Radiative Transfer》2011,112(10):1525-1532
Global climate models require accurate and rapid computation of the radiative transfer through the atmosphere. Correlated-k methods are often used. One of the approximations used in correlated-k models is the weak-line approximation. We introduce an approximation Tγ which reduces to the weak-line limit when optical depths are small, and captures the deviation from the weak-line limit as the extinction deviates from the weak-line limit. This approximation is constructed to match the first two moments of the gamma distribution to the k-distribution of the transmission. We compare the errors of the weak-line approximation with Tγ in the context of a water vapor spectrum. The extension Tγ is more accurate and converges more rapidly than the weak-line approximation. 相似文献
12.
In situ monitoring of nucleation and evolution of Ge nanodots on faintly oxidized Si(1 1 1) surfaces
We have investigated the nucleation and evolution of germanium (Ge) nanodot (ND)s taking place while depositing Ge onto the silicon (Si) (1 1 1) surfaces with ultra-thin Si oxide films by using ultra-high vacuum in situ high-resolution transmission electron microscopy in the profile-imaging geometry. Various types of growth phenomena such as nucleation, growth and coalescence of Ge NDs have successfully been observed. The results show that the growth phenomena of the Ge NDs are dramatically rapid after their size reaches the size of the critical nucleus. The critical nucleus size estimated from a model using the cohesive energy of the Ge NDs has been consistent with observed one. 相似文献
13.
L.G. Gao K.B. Yin L. Chen H.X. Guo Y.D. Xia J. Yin Z.G. Liu 《Applied Surface Science》2009,256(1):90-95
Thermal stability, interfacial structures and electrical properties of amorphous (La2O3)0.5(SiO2)0.5 (LSO) films deposited by using pulsed laser deposition (PLD) on Si (1 0 0) and NH3 nitrided Si (1 0 0) substrates were comparatively investigated. The LSO films keep the amorphous state up to a high annealing temperature of 900 °C. HRTEM observations and XPS analyses showed that the surface nitridation of silicon wafer using NH3 can result in the formation of the passivation layer, which effectively suppresses the excessive growth of the interfacial layer between LSO film and silicon wafer after high-temperature annealing process. The Pt/LSO/nitrided Si capacitors annealed at high temperature exhibit smaller CET and EOT, a less flatband voltage shift, a negligible hysteresis loop, a smaller equivalent dielectric charge density, and a much lower gate leakage current density as compared with that of the Pt/LSO/Si capacitors without Si surface nitridation. 相似文献
14.
Peak assignment is a complex but important task for analyzing the vibration spectra of surface-bound molecules. Here we describe a simple approach for calculating infrared and Raman spectra for surface-bound molecules using a cluster model approach with quantum capping potentials (QCPs). The utility of the approach is demonstrated by comparisons to the measured high resolution electron energy loss spectra for ethylene on clean silicon. By capping the silicon cluster with QCPs we computed spectra that agree very well with the HREEL spectrum, allowing us to easily assign the experimental peaks. QCPs are similar to effective core potentials, can be used with any ab initio technique and most computational chemistry packages, and their use requires no special expertise. 相似文献