共查询到19条相似文献,搜索用时 140 毫秒
1.
使用三氟甲烷和苯的混合气体,利用微波电子回旋共振等离子体增强化学气相沉积法制备了F/C比在0.11—0.62之间的α-C∶F薄膜.研究了微波功率对薄膜沉积和结构的影响,发现微波功率的升高提高了薄膜的沉积速率,降低了薄膜的F/C比,也降低了薄膜中CF和CF3基团的密度,而使CF2基团的密度保持不变.在高微波功率下可以获得主要由CF2基团和C=C结构组成的α-C∶F薄膜.薄膜的介电频率关系(1×103—1×106Hz)和损耗频率关系(1×102—1×105Hz)均呈指数规律减小,是缺陷中心间简单隧穿引起的跳跃导电所致.α-C∶F薄膜的介电极化主要来源于电子极化
关键词:
氟化非晶碳薄膜
ECR等离子体沉积
键结构
介电性质 相似文献
2.
利用电子束沉积技术首次制备了氟化铒 (ErF3) 掺杂的氧化铟(In2O3)透明导电薄膜(IEFO),研究了薄膜的晶体结构、光学特性和电学特性。利用原子力显微镜测试了不同厚度薄膜的形貌,初步研究了薄膜的生长过程。研究发现:IEFO薄膜为多晶结构,Er原子的掺入改变了薄膜的优势生长方向,使薄膜在(211)、(222)、(444)3个方向上的生长趋势基本相同。 薄膜电阻率为1.265×10-3 Ω·cm,电子迁移率为45.76 cm2·V-1·s-1,电子浓度为1.197×1020 cm-3,在380~780 nm范围内的可见光平均透过率为81%。 相似文献
3.
采用零维等离子体动力学模型,计算了不同约化场强条件下N2/O2放电等离子体的演化特性.结果表明,平均电子能量与约化场强有着近似的线性关系,在约化场强为100 Td时,平均电子能量约为2.6 eV、最大电子能量达35 eV;约化场强是影响电子能量函数分布的主要因素.气体放电过程结束后,振动激发态氮分子的粒子数浓度不再变化,电子激发态的氮分子、原子和氧原子的粒子数浓度达到一峰值后开始降低;放电结束后的氧原子通过复合反应生成臭氧.约化场强升高,由于低能电子减少的影响,振动激发态氮分子的粒子数浓度降低,当约化场强由50 Td增加75 Td,100 Td时,粒子数浓度由3.83×1011 cm-3降至1.98×1011 cm-3和1.77×1011 cm-3,其他粒子浓度则相应增大.
关键词:
等离子体
约化场强
粒子演化
数值模拟 相似文献
4.
采用静电探针技术对微波电子回旋共振(MW-ECR) 等离子体进行了诊断,利用等离子体增强 非平衡磁控溅射(PE-UMS)法在常温下制备了Zr-N薄膜, 通过EPMA,XRD,显微硬度对膜的 结构和性能进行评价.实验结果表明,随氮气流量增加,总的等离子体密度从807×109c m-3增加到831×109cm-3然后逐渐减小为752×10 9cm-3;而N2+密度则从312×108< /sup>cm-3线性递增到335×109cm-3;电子温度变化 不大.对薄膜而言,随N2+密度增大,样品中氮含量增加,而晶粒逐 渐变小,当样品中N/ Zr原子比达到14时,薄膜中出现亚稳态的Zr3N4相以及非晶相, 在更高氮流量下,整 个薄膜转变为非晶态.与此相应,薄膜硬度由最初的225GPa增大到2678GPa 然后逐渐减 小到1982GPa.
关键词:
氮化锆薄膜
ECR等离子体
磁控溅射
诊断 相似文献
5.
采用光抽运-太赫兹探测技术研究Cd0.96Zn0.04Te的载流子弛豫和瞬:态电导率特性.在中心波长800 nm的飞秒抽运光激发下,Cd0.96Zn0.04Te的载流子弛豫过程用单指数函数进行了拟合,其载流子弛豫时间长达几个纳秒,且在一定光激发载流子浓度范围内随光激发载流子浓度的增大而减小,这与电子-空穴对的辐射复合有关.在低.光激发载流子浓度(4.51×1016—1.81×1017 cm-3)下,Cd0.96Zn0.04Te的太赫兹(terahertz,THz)瞬态透射变化率不随光激发载流子浓度增大而变化,主要是由于陷阱填充效应造成的载流子损失与光激发新增的载流子数量近似.随着光激发载流子浓度继续增大(1.81×1017—1.44×1018 cm-3),THz瞬态透射变化率随光激发载流子浓度的增大而线性增大,是由于缺陷逐渐被... 相似文献
6.
通过微波电子回旋共振等离子体化学气相沉积方法使用CH4/CHF3源气体制备a-C∶F∶H薄膜.红外结果表明,a-C∶F∶H薄膜随着流量比R=[CHF3]/[CHF3]+[CH4])的变化存在结构上的演变,R<64%时,薄膜主要是以类金刚石(DLC)特征的结构为主;当R>64%时,薄膜表现为一个类聚四氟乙烯(PTFE)的结构,结构单体主要为CF2.同时这种结构上的变化影响着薄膜
关键词:
a-C∶F∶H薄膜
傅里叶变换红外光谱
紫外可见光谱 相似文献
7.
采用电子束蒸发Pt和后快速热退火的方法,研究了退火条件对Pt纳米晶的生长特性的影响,结果显示Pt纳米晶的密度随退火温度的升高和退火时间的延长均表现出先增大后减小的趋势.在800℃下退火20 s能得到分布均匀的、密度为30×1011 cm-2的Pt纳米晶.进一步研究了基于Al2O3/Pt纳米晶/HfO2叠层的MOS电容结构的存储效应,表明其在-3—+8 V扫描电压范围下C-V<
关键词:
Pt纳米晶
快速热退火
原子层淀积
存储效应 相似文献
8.
为了描述在晶体生长阶段掺入[Fe(CN)6]4-的立方体AgCl微晶中 光电子的产生与 衰减过程,建立了一种由三个固有中心和一个浅电子陷阱(SETs)组成的动力学模型,并引出一组微分方程.通过求解微分方程得到与实验结果相符合的光电子衰减曲线及其寿命.调整相 关模拟参数,于常温下得到由[Fe(CN)6]4-引入的SETs阱深为0.1 15eV,电子俘获截面为2.136×10-17cm2.
关键词:
光电子
浅电子陷阱
俘获截面
AgCl微晶 相似文献
9.
10.
本文利用流体模型对气压为266 Pa的氧气环境下空心阴极放电的放电特性及不同粒子的生成损耗机制进行了模拟研究.模型中包含11种粒子和48个反应.在该模拟条件下,周围阴极所对应的负辉区产生重叠,表明放电中存在较强的空心阴极效应.计算得到了不同带电粒子与活性粒子的密度分布.带电粒子密度主要位于放电单元中心区域,电子和负氧离子O~-是放电体系中主要的负电荷,其密度峰值分别达到5.0×1011 cm-3和1.6×1011 cm-3;O2~+是放电体系中主要的正电荷,其密度峰值为6.5×1011 cm-3.放电体系中同时存在丰富的活性氧粒子,并且其密度远高于带电粒子,按其密度高低依次为基态氧原子O、单重激发态氧分子O2(a~1Δg)、激发态氧原子O(~1D)、臭氧分子O3.对电子、O~-和O2~+的生成和损耗的反应动力学过程进行了深入分析,同时给出了不同活性... 相似文献
11.
We report photoemission results from which we directly determined the density of states g(E) in the gap of a-Si:H between the top of the valence band Ev and the Fermi level. At 0.4 eV above Ev, g(E) was found to be ≈1×1020 cm-3 eV-1 in the undoped film; P-doping increased g(E) in this region whereas annealing reduced it. The photoconductivity-derived optical absorption spectrum matched the shape of the photoemission spectrum, and thus supports the explanation that the photoconductivity shoulder at photon energies in the region of 1.3 eV is due to transitions from localized states above the valence band to the conduction band. 相似文献
12.
Influence of 60Co gamma radiation on fluorine plasma treated enhancement-mode high- electron-mobility transistor 下载免费PDF全文
AlGaN/GaN depletion-mode high-electron-mobility transistor(D-HEMT) and fluorine(F) plasma treated enhancement-mode high-electron-mobility transistor(E-HEMT) are exposed to 60Co gamma radiation with a dose of 1.6 Mrad(Si).No degradation is observed in the performance of D-HEMT.However,the maximum transconductance of E-HEMT is increased after radiation.The 2DEG density and the mobility are calculated from the results of capacitance-voltage measurement.The electron mobility decreases after fluorine plasma treatment and recovers after radiation.Conductance measurements in a frequency range from 10 kHz to 1 MHz are used to characterize the trapping effects in the devices.A new type of trap is observed in the F plasma treated E-HEMT compared with the D-HEMT,but the density of the trap decreases by radiation.Fitting of G p /ω data yields the trap densities D T =(1-3) × 10 12 cm-2 · eV-1 and D T =(0.2 0.8) × 10 12 cm-2 ·eV-1 before and after radiation,respectively.The time constant is 0.5 ms-6 ms.With F plasma treatment,the trap is introduced by etch damage and degrades the electronic mobility.After 60Co gamma radiation,the etch damage decreases and the electron mobility is improved.The gamma radiation can recover the etch damage caused by F plasma treatment. 相似文献
13.
14.
Zirconium oxide layers have been successfully deposited by photo-CVD at low temperatures. ZrO2 growth was observed at temperatures as low as 100 °C. When deposited at 250 °C and above, these films exhibited a polycrystalline
structure with a mixture of different crystal phases. Deposition at 300 °C was found to form moisture-free ZrO2 films with a high refractive index of 2.1, a very low effective density of trapped electrons of ∼8.8×108 cm-2 and an interface trap density of 6.6×109 cm-2 eV-1 being readily obtained.
Received: 17 December 2001 / Accepted: 6 January 2002 / Published online: 3 June 2002 相似文献
15.
Identification and elimination of inductively coupled plasma-induced defects in AlxGa1 - xN/GaN heterostructures 下载免费PDF全文
By using temperature-dependent Hall,variable-frequency capacitance-voltage and cathodoluminescence (CL) measurements,the identification of inductively coupled plasma (ICP)-induced defect states around the Al x Ga 1-x N/GaN heterointerface and their elimination by subsequent annealing in Al x Ga 1-x N/GaN heterostructures are systematically investigated.The energy levels of interface states with activation energies in a range from 0.211 to 0.253 eV below the conduction band of GaN are observed.The interface state density after the ICP-etching process is as high as 2.75×10 12 cm 2 ·eV 1.The ICP-induced interface states could be reduced by two orders of magnitude by subsequent annealing in N 2 ambient.The CL studies indicate that the ICP-induced defects should be Ga-vacancy related. 相似文献
16.
Investigation of AlGaN/GaN fluorine plasma treatment enhancement-mode high electronic mobility transistors by frequency-dependent capacitance and conductance analysis 下载免费PDF全文
This paper reports fluorine plasma treatment enhancement-mode HEMTs (high electronic mobility transistors) EHEMTs and conventional depletion-mode HEMTs DHEMTs fabricated on one wafer using separate litho-photography technology. It finds that fluorine plasma etches the AlGaN at a slow rate by capacitance--voltage measurement. Using capacitance--frequency measurement, it finds one type of trap in conventional DHEMTs with τT=(0.5-6) ms and DT= (1 - 5) × 1013 cm-2·eV-1. Two types of trap are found in fluorine plasma treatment EHEMTs, fast with τT(f)=(0.2-2) μs and slow with τT(s)=(0.5-6) ms. The density of trap states evaluated on the EHEMTs is DT(f)=(1 - 3) × 1012 cm-2·eV-1 and DT(s)=(2 - 6) × 1012 cm-2·eV-1 for the fast and slow traps, respectively. The result shows that the fluorine plasma treatment reduces the slow trap density by about one order, but introduces a new type of fast trap. The slow trap is suggested to be a surface trap, related to the gate leakage current. 相似文献
17.
T. Kamiya A. Suemasu T. Watanabe T. Sameshima I. Shimizu 《Applied Physics A: Materials Science & Processing》2001,73(2):151-159
The carrier transport property of polycrystalline silicon (poly-Si:H:F) thin films was studied in relation to film microstructure,
impurity, in situ or post-annealing treatments to obtain better carrier transport properties. Poly-Si:H:F films were prepared
from SiF4 and H2 gas mixtures at temperatures <300 °C. Dark conductivity of the films prepared at high SiF4/H2 gas flow ratio (e.g., 60/3 sccm) exhibits a high value for intrinsic silicon and its Fermi level is located near the conduction
band edge. The carrier incorporation is suppressed well, either by in situ hydrogen plasma treatment or by post-annealing
with high-pressure hot-H2O vapor. It is confirmed that weak-bonded hydrogen atoms are removed by the hot-H2O vapor annealing. In addition, evident correlation between impurity concentrations and dark conductivity is not found for
these films. It is thought that the carrier incorporation in the films prepared at high SiF4/H2 gas flow ratios is related to grain-boundary defects such as weak-bonded hydrogen. By applying hot-H2O vapor annealing at 310 °C to a 1-μm-thick p-doped (400)-oriented poly-Si:H:F film, Hall mobility was improved from 10 cm2/Vs to 17 cm2/Vs.
Received: 7 August 2000 / Accepted: 2 March 2001 / Published online: 20 June 2001 相似文献
18.
C. Viswanathan S. Gopal D. Mangalaraj Sa. K. Narayandass O. F. Caltun G. Rusu Junsin Yi 《Ionics》2004,10(3-4):311-316
The InSe films of different thicknesses (290–730 mm) were deposited onto glass substrates under a pressure of 3×10?5 Torr by vacuum evaporation method. The composition (In=53.50%, Se=46.50%) of this film was confirmed using Auger Electron Spectroscopy (AES). Thicknesses of the deposited films have been measured using a Multiple Beam Interferometry. The amorphous nature of the film is confirmed with X-ray diffractogram. From the transmittance spectra in the range of 500 nm-1200 nm, it is observed that the film showed direct allowed transition. Effect of thickness on the optical parameters such as the fundamental band gap, absorption constant, refractive index of InSe thin films are reported. Under low electric field (~ 1.5×105 Vcm?1), the results of DC conductivity measurements revealed that the variable range hopping is the dominant conduction mechanism. The values of localized states density, localization radius and hopping energy of this film are estimated as 5.57×1020 cm?3eV?1, 0.84 Å and 0.247 eV, respectively. 相似文献
19.
Wen Yang Qing-Qing Sun Run-Chen Fang Lin Chen Peng Zhou Shi-Jin Ding David Wei Zhang 《Current Applied Physics》2012,12(6):1445-1447
HfLaOx based Metal–oxide–semiconductor capacitors were fabricated by atomic layer deposition in this work. The material and electrical properties of the films along with the high temperature thermal treatment were investigated. It was found that samples undergoing annealing at 900 °C exhibited the best performance. The film was found to be crystallized to a cubic structure at 900 °C, and the roughness of the films was estimated to be 0.332 nm. For electrical characterization, the C–V curve of the film is in good agreement with the corresponding simulated curve, and the capacitor does not show any hysteresis. Moreover, the Dit near the center of silicon band gap exhibits lowest value, and it was calculated to be 2.28 × 1011 eV?1 cm?2. 相似文献