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1.
Schottky barrier SOI-MOSFETs incorporating a La2O3/ZrO2 high-k dielectric stack deposited by atomic layer deposition are investigated. As the La precursor tris(N,N′-diisopropylformamidinato) lanthanum is used. As a mid-gap metal gate electrode TiN capped with W is applied. Processing parameters are optimized to issue a minimal overall thermal budget and an improved device performance. As a result, the overall thermal load was kept as low as 350, 400 or 500 °C. Excellent drive current properties, low interface trap densities of 1.9 × 1011 eV−1 cm−2, a low subthreshold slope of 70-80 mV/decade, and an ION/IOFF current ratio greater than 2 × 106 are obtained.  相似文献   

2.
A method is described in which monocrystalline layers, evaporated on to monocrystalline substrates, are doped during the evaporation. The doping efficiency shows a different behaviour for p- and n-type impurities and is concentration dependent. UHF transistors have been made structures containing two layers by this method.  相似文献   

3.
The study of ultrathin ZrO2 films grown on surface passivated germanium substrates by plasma enhanced Atomic Layer Deposition (PEALD) has been carried out. Nitride passivation has been used to form an interfacial layer between ZrO2/Ge. The ultra-thin ZrO2 film deposited with thickness of ~5.75 nm and refractive index of ~2.05 as observed through ellipsometry. The Ge3d, Zr3d, N1s and O1s are XPS core level spectra's confirm the formation of GeON and ZrO2 ultra-thin films. The AFM results show the roughness of deposited films as low as 0.3 nm. The effect of post metallization annealing (PMA) on electrical properties of Au/Cr/ZrO2/GeON/Ge capacitors has been investigated. The improvement in k value (~38) and an EOT value (~0.5 nm) after PMA on Ge/GeON/ZrO2 stack has been observed. The flat band voltage and hysteresis of post metallization annealed devices has been reduced as compared to that of without PMA GeON/ZrO2 stack.  相似文献   

4.
Complete ionization of impurity atoms in semiconductors which is the most common engineering assumption is found to breakdown in the heavily doped condition [1]. Here a calculation of the degree of ionization in degenerate germanium for different doping concentrations is presented.  相似文献   

5.
Modern bipolar transistors use polysilicon emitters and an epitaxial grown silicon germanium (SiGe) base. For device optimization, both the SiGe base and the region of the diffused emitter is of special interest. In this paper, electron holography is applied to visualize and directly measure the two-dimensional distribution of the local potential in a high-performance SiGe heterojunction bipolar transistor. Special emphasis is put on investigating the region of the emitter diffused into the epitaxially grown base layer. In addition, we investigate the self-aligned base-link construction. We compare electron holographic measurements of the whole transistor to secondary ion mass spectrometric (SIMS) data and discuss the results.  相似文献   

6.
Pure and Ce doped ZrO2 nanostructures have been synthesized by the microwave irradiation method. The prepared nanoparticles were characterized by various analytical techniques like Thermogravimetric and Differential Thermal Analysis (TG–DTA), X-Ray Diffraction (XRD), Fourier Transform Infra-Red Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive Spectrum (EDS) and Transmission Electron Microscopy (TEM). The XRD pattern of Ce doped ZrO2 nanoparticles have been confirms that the tetragonal structure. TEM observations indicated that the average particle size of the pure ZrO2 some particles spherical shaped and some particles agglomeration in the range of 16–44 nm. Whereas on addition of Ce agglomeration in the range of 32–56 nm. The pure ZrO2 and Ce doped ZrO2 nanoparticles were further characterized for their optical properties by UV–vis reflectance spectra (DRS) and Photoluminescence (PL) spectroscopy.  相似文献   

7.
The letter analyses the performance of a two-link binary coherent phase-shift-keying (CPSK) communication system incorporating a direct phase regenerator (DPR) with imperfect carrier reference signals in the regenerator and the receiver. These references are extracted from the received signals by means of squaring loops. Additive Gaussian noise (AGN) is considered at the inputs of the DPR and the receiver.  相似文献   

8.
MOS devices built on various germanium substrates, with chemical vapor deposited (CVD) or physical vapor deposited (PVD) HfO/sub 2/ high-/spl kappa/ dielectric and TaN gate electrode, were fabricated. The electrical properties of these devices, including the capacitance equivalent thickness (CET), gate leakage current density (J/sub g/), slow trap density (D/sub st/), breakdown voltage (V/sub bd/), capacitance-voltage (C-V) frequency dispersion, and thermal stability, are investigated. The process conditions such as surface nitridation treatment, O/sub 2/ introduction in CVD process and postdeposition anneal temperature in PVD process, exhibit significant impacts on the devices' electrical properties. The devices built on germanium substrates with different dopant types and doping concentrations show remarkable variations in electrical characteristics, revealing the role of the substrate doping in the reactions occurring at the dielectric/Ge interface, which can significantly affect the interfacial layer formation and Ge updiffusion. A possible mechanism is suggested that two competing processes (oxide growth and desorption) take place at the interface, which govern the formation of the interfacial layer. Doped p-type (Ga) and n-type (Sb) impurities may enhance the different process at the interface and cause the variations in the interfacial layer formation and so on in electrical properties. The high diffusivities of impurities and Ge atoms in Ge and the induced structural defects near the substrate surface could be one possible cause for this doping effect. As another behavior of the substrate doping effect, Ge n-MOS and p-MOS stacks show quite different C-V characteristics after high temperature postmetallization anneal treatments, which can be explained by the same mechanism.  相似文献   

9.
用电子陶瓷工艺制备了三种不同掺杂比例的临界热敏电阻CTR(Critical Temperature Resister),根据样品对应的热谱中的相变点,找出Fe2O3掺杂量与相变点的关系。从微观半导体理论分析晶粒体电特性,求解泊松方程,得出晶粒体中电势垒与受主杂质Fe2O3掺杂量的关系。结果表明:当x(Fe2O3)为10%~25%时,相变温度增加值?t和摩尔分数增加值(?x)2呈线性关系。  相似文献   

10.
In this work we present a simple technique for laser frequency stabilization, based on Digital signal processing. The technique is used to stabilize a waveguide CO2 laser of wide tunability by using three kinds of reference signals: the CO2 laser ouptut power, an infrared absorption optoacoustic signal and the output power of a Far-Infrared optically pumped molecular laser.  相似文献   

11.
ZnO-V_2O_5系压敏电阻器的掺杂改性   总被引:2,自引:3,他引:2  
用掺B2O3和K+的方法改善ZnO-V2O5多元系压敏电阻器的性能。实验结果表明B2O3能起到液相促烧作用,同时也会影响材料的电性能。掺适量的K+能改善漏电流、非线性系数等电性能。  相似文献   

12.
描述了KrF准分子激光对氧化锆陶瓷的微刻蚀实验,研究了脉冲刻蚀深度与脉冲数的关系(刻蚀速率),刻蚀的槽的形貌,并进行了刻蚀小孔的初步研究,得到直径为40μm,深度为25μm的微孔矩阵。为KrF激光对该材料的加工提供实验数据。  相似文献   

13.
研究了一种新的制备PZT/ZrO2复合陶瓷材料的方法。借助B位先驱体法,首先合成亚稳态的钙钛矿固溶体,在高温下ZrO2相从固溶体中析出得到PZT/ZrO2复合陶瓷材料。在冷却过程中,已在PZT晶粒内析出的ZrO2相发生四方到单斜的相变,伴随该相变的体积膨胀会对晶界产生压应力,起到强化晶界的作用,从而使陶瓷材料的力学性能得到明显提高。  相似文献   

14.
ZrO2 thin films have been prepared by laser ablation of Zr or ZrO2 targets in oxygen reactive atmosphere. The influence of the deposition parameters as oxygen pressure and target composition on the structure and morphology of the deposited layers has been studied. Scanning electron microscopy, secondary ion mass spectroscopy and dielectric constant measurements have been performed to characterize the deposited layers. Dielectric constant values in the range 15–20 and low losses were evidenced for samples prepared in a narrow range of experimental conditions.  相似文献   

15.
Aspects of the formation of self-organized clusters of germanium (Ge) and solid solution of SiGe, first formed in the mode of deposition of subthin polycrystalline silicon films doped with Ge on the nanoscale film of dielectrics were studied by techniques of atomic force microscopy and Raman scattering by optical phonons in germanium clusters. We found that in subthin polycrystalline silicon films (PSF) doped with Ge on the nanoscale films of dielectrics in conditions of PSF film deposition, there appeared correlated spatial distribution of germanium clusters, as well as silicon rich clusters in certain conditions, i.e., clusters of SiGe solid solution, with the modes of their formation. The relationship of the form, size, and density of Ge nanoclusters (NC), with the conditions of their self-organization is considered. The influence of interdiffusion processes on self-organizing of clusters is established, which is significant at high temperatures of the deposition and doping of PSF. It was found that clusters (islands) could occur on the cleavage surface in the form of four types of topographic features in a classical pyramid form, flat-topped pyramids, and domes and sharp spines, depending on the conditions of the deposition of PSF doped with Ge. The systems of highly organized Ge NC, measuring 3.5–40 nm and with a density of 2.7 × 107–3.5 × 10 cm−2 were obtained. The possibility, in principle, of managing the geometric parameters of self-organizing NC (nanoislands) by selecting the conditions of their self-organization in the mode of deposition of PSF doped with Ge, was shown.  相似文献   

16.
An improved method of designing optimal minimum phase FIR filters by directly finding zeros is proposed. The zeros off the unit circle are found by an efficient special purpose root-finding algorithm without deflation. The proposed algorithm utilizes the passband minimum ripple frequencies to establish the initial points, and employs a modified Newton's iteration to find the accurate initial points for a standard Newton's iteration. We show, with examples, that the proposed algorithm can be used to design very long filters (L = 325) with very high stopband attenuations.  相似文献   

17.
《Microelectronic Engineering》2007,84(9-10):1861-1864
We have developed a process for forming an ultra-thin HfSiOx interfacial layer (HfSiOx-IL) for high-k gate stacks. The HfSiOx-IL was grown by the solid-phase reaction between HfO2 and Si-substrate performed by repeating the sequence of ALD HfO2 deposition and RTA. The HfSiOx-IL grown by this method enables the formation of very uniform films consisting of a few mono-layers, and the dielectric constant of the HfSiOx-IL is about 7. The FUSI-NiSi/HfO2 gate stacks with HfSiOx-IL have achieved 0.6 nm EOT, a very low gate leakage currents between 1 A/cm2 and 5 × 10−2 A/cm2, an excellent subthreshold swing of 66mV/dec, and a high peak mobility of 160 cm2/Vs compared to the reference samples without HfSiOx-IL. These results indicate that the HfSiOx-IL has a good quality compared to the SiO2 interfacial layer grown by oxygen diffusion through HfO2 films.  相似文献   

18.
A broad compositional range of the dielectric material Zr1?xHfxO2 was evaluated with respect to its applicability in DRAM storage capacitors. The paper reports on phase composition, crystallization behavior, and electrical properties of the mixed system in planar metal-insulator-metal (MIM) capacitors. Admixture of HfO2 into ZrO2 proved to stabilize the deposition process at high temperatures without degrading the dielectric properties of the film. Compared to pure ZrO2 the 30–40% HfO2 containing films showed improved scalability (capacitance equivalent thickness 0.73 nm at 8 * 10?9 A/cm2) as well as improved reliability.  相似文献   

19.
利用一步激光直写灰阶光刻方法制作了具有连续浮雕结构的透射式相位光栅.原子力显微镜测量结果表明制作的透射式相位光栅具有连续外形轮廓、理想的周期和深度.飞秒激光实验系统测量的光栅的衍射效率结果表明:最大衍射角效率为66.8%、零级能量仅为入射光能量的3.3%,这在光限幅中有重要应用价值.  相似文献   

20.
以Zr(OC3H7)4为前驱体,乙酰丙酮为络合剂,在盐酸的酸性条件下,于乙醇溶剂中水解制备ZrO2溶胶.采用粘度、红外(IR)光谱、折射率、热分析(DSC)、原子力显微镜(AFM)等测试手段对溶胶和薄膜性能进行表征.结果表明,制备的ZrO2溶胶具有比较好的粘度稳定性,加入聚乙烯吡喏烷酮(PVP)对溶胶稳定性影响不大;经500 ℃热处理后,膜层折射率可达1.91;薄膜表面均匀平整;加入PVP能提高膜层的激光损伤阈值(LIDT),ZrO2膜的激光损伤阈值为19.6 J/cm2(1064 nm,1 ns),ZrO2-PVP膜的激光损伤阈值为23.3 J/cm2(1064 nm,1 ns).  相似文献   

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