Fowler—Nordheim公式用于实际场发射体的修正

Ｆｏｗｌｅｒ－Ｎｏｒｄｈｅｉｍ公式是一个在理想条件下推导的计算场致发射电流的公式。对场发射体的实验测量表明；实测结果往往比根据Ｆｏｗｌｅｒ－Ｎｏｒｄｈｅｉｍ公式计算的结果大很多，说明这一理想化了的公式应用于实际场发射体时，必须给予修正。本文讨论了产生这一问题的原因，并提出了合理的定量修正方法。     

Fowler－Nordheim公式应用于实际场发射体的修正

Ｆｏｗｌｅｒ－Ｎｏｒｄｂｅｉｍ公式是一个在理想条件下推导的计算场致发射电流的公式。对场发射体的实验测量表明：实验结果往往比根据Ｆｏｗｌｅｒ－Ｎｏｒｄｈｅｉｍ公式计算的结果大得很多，说明这一理想化了的公式应用于实际场发射体时，必需得到修正。本文讨论了产生这一问题的原因，并提出了合理的定量修正方法。     

氧化物中固定电荷对硅场致发射的影响

本文给出了硅表面覆盖氧化层时，场发射电流的解析公式．考虑了固定氧化物电行时场致发射的影响．结果表明，氧化物和固定电荷均使场发射电流减小，场发射Ｆｏｗｌｅｒ－Ｎｏｒｄｈｅｉｍ图中有两个明显的线性区．     

多孔硅场致发射特性研究

目前真空微电子使用的场致发射电子源主要是在硅衬底上采用腐蚀法和生长法得到的场发射阵列。这种方法在制造上难度较大，也很复杂。本文介绍用阳极化的方法制造多孔硅场发射阵列，并通过实验测定，用此法制造的场发射尖端阵列的发射曲此，很好地符合Ｆｏｗｌｅｒ－Ｎｏｒｄｈｅｉｍ公式。     

含F栅介质的Fowler-Nordheim效应

本文建立了一套用于ＭＯＳ电容热载流子损伤研究的自动测试分析系统，用高频和准静态Ｃ－Ｖ技术，分析研究了栅介质中Ｆ离子的引入所具有的抑制Ｆｏｗｌｅｒ－Ｎｏｒｄｈｅｉｍ高场应力损伤的特性，对Ｆ离子和高场应力作用机制进行了讨论．     

电化学生长法制备薄膜阵列场致发射阴极的研究

本文介绍一种制备薄膜场发射阵列阴极的新方法，这就是以玻璃为衬底的电化学生长法。文章给出了用这种方法生成的铜尖端阵列的形貌和结构，并给出了它的发射曲线。这些曲线表明，它们很好地与Ｆｏｅｌｅｒ－Ｎｏｒｄｈｅｉｍ公式一致。     

氮生长掺杂和离子注入掺杂CVD金刚石薄膜的场电子发射

本文研究了氮生长掺杂和离子注入掺杂金刚石薄膜的场电子发射性能．测试结果表明,两类样品均显示良好的发射性能,即开启电压低（５０～１５０Ｖ）、发射电流大（６～３０ｍＡ）,但它们有不同的发射行为：注入掺杂样品存在发射电流的饱和与滞后、开启电压的前移现象,而生长掺杂样品的发射符合Ｆｏｗｌｅｒ－Ｎｏｒｄｈｅｉｍ理论．实验还得到了用于生长场发射阴极薄膜的最佳掺杂氮碳流量比为～４２％．     

改进的FD—TD法分析二维理想导体TM近区散射问题

本文针对一般ＦＤ－ＴＤ方法分析计算二维理想导体散射问题所遇到散射体边角处难以精确处理的缺点进行了改进。将边角处总场近似解析解直接引入ＦＤ－ＴＤ法差分公式，得到了有关修正系数，为了检验此方法的有效性，有无限长导体方柱为例分别用一般ＦＤ－ＴＤ法和本文的ＦＤ－ＴＤ方法进行了分析研究，并与ＭＯＭ法进行了比较，所得结果说明改进后的ＦＤ－ＴＤ方法对分析计算导体边角附近电流分布特性是较有效的。     

Fowler—Nordheim高电场应力引起的MOS结构损伤研究

本文研究了Ｆｏｗｌｅｒ－Ｎｏｒｄｈｅｉｍ高电场应力引起的ＭＯＳ结构损伤及其室温退火。结果表明有四种损伤产生，氧化物正电荷建立，Ｓｉ／ＳｉＯ２快界面态增长，慢界面态产生和栅介质电容下降，当终止应力后，前三种损伤在室温下有所恢复，但最后一种损伤没有变化，实验还表明：产生的慢界面态分布在禁带上半部；高电场下栅介电容呈现无规阶梯型下降，对四种损伤及其室温退火机理进行了讨论，还给出产生的慢界面态对高频电容－     

Fowler－Nordheim高电场应力引起的MOS结构损伤研究

本文研究了Ｆｏｗｌｅｒ－Ｎｏｒｄｈｅｉｍ高电场应力引起的ＭＯＳ结构损伤及其室温退火．结果表明有四种损伤产生：氧化物正电荷建立、Ｓｉ／ＳｉＯ２快界面态增长、慢界面态产生和栅介质电容下降．当终止应力后，前三种损伤在室温下有所恢复，但最后一种损伤没有变化．实验还表明：产生的慢界面态分布在禁带上半部；高电场下栅介质电容呈现无规阶梯型下降．对四种损伤及其室温退火机理进行了讨论．还给出产生的慢界面态对高频电容－电压测量的影响．     

On relationship between the field at an autoemitter top, anode voltage and cathode geometry

Currently a lot of electron emission experiments both in carbon nanotubes with top curvature radius <1 nm, and in emitters as short as 10³ nm with top curvature radius of some tens nanometer are carried out. Experimental results can be explained by a tunnel emission through potential barrier in vacuum near the solid-state cathode border making use of Fowler-Nordheim law. However, in case of cathodes with radius of top curvature less than 100 nm this law is not valid.To proof this statement, the potential of an autoemission diode consisting of a tip cathode located on a flat metal base and flat anode, its dependence on the shape, height of the tip as well as voltage drop on it were calculated in this paper. It has been shown that with cathode tip height and its radius of curvature decreasing (?100 nm) the transparency of the potential barrier depends non-linearly on the anode voltage in the Fowler-Nordheim coordinates when the cathode tip height decreases from 1000 down to 150 nm. To obtain a measurable autoemission current, work function must not exceed the uniform field’s potential drop between cathode top and its base. Deduced is the analytic formula for the electric field potential that extends approximation features for real cathodes shapes and enables more accurate electric field modeling at the surface.     

Numerical study on performance of pyramidal and conical isotropic etched single emitters

A full three-dimensional model was implemented in order to investigate the electrical characteristics of conical and pyramidal isotropic etched emitters. The analysis was performed using the finite element method (FEM). The simulations of both emitters were modeled using a combination of tetrahedral and hexahedral elements that are capable of creating a mapped and regular mesh in the vacuum region and an irregular mesh near the surfaces of the emitter. The electric field strengths and electric potentials are computed and can be used to estimate the field enhancement factor as well as the current density using the Fowler-Nordheim (FN) theory. The FEM provides results at nodes located at discrete coordinates in space; therefore, the surface of the emitter can be generated through a function interpolating a set of scattered data points. The emission current is calculated through integration of the current density over the emitter tip surface. The influences of the device geometrical structure on its potential distribution, electric field and emission characteristics are discussed.     

真空微电子器件应用研究

本文叙述了场致发射的机理及几种不同类型场致发射阴极的特点,并对场致发射技术在真空微电子器件方面的应用进行了分析.     

Improved field emission characteristic of carbon nanotubes by an Ag micro-particle intermediation layer

An efficient way to improve field emission characteristic of carbon nanotubes (CNTs) through an Ag micro-particle intermediation layer is presented. In this way, the intermediation layer is deposited on an indium tin oxide glass substrate by electrochemical method and then the CNTs are covered onto surface of the intermediation layer by electrophoretic method as CNT field emitters. The field emission characteristic of the CNT field emitters with the intermediation layer is significantly improved compared to the one without the intermediation layer, including decreased turn-on electric field from 4.2 to 3.1 V/μm and increased emission current density from 0.224 to 0.912 mA/cm² at an applied electric field of 6 V/μm. The improved field emission characteristic may be attributed to gibbous surface of the CNT field emitters. This efficient way is much simple, low cost, and suitable for production of large scale CNTs–based field emission cold cathode.     

用场发射显微镜测量单壁碳纳米管的逸出功

该文利用场发射显微镜对单壁碳纳米管的逸出功进行了研究和测量。未进行加热除气的单壁碳纳米管的表面吸附大量气体,此时测量的逸出功不是清洁表面单壁碳纳米管的逸出功。实验首先加热除气得到单壁碳纳米管的场发射清洁像,然后利用场发射显微镜测量I-V曲线,得到Fowler-Nordheim直线斜率;再利用透射电镜观测单壁碳纳米管微束形貌像,测量管束半径,通过三种公式估算比例因子,最后计算得到单壁碳纳米管的逸出功。     

Lateral field emission diodes using SIMOX wafer

Lateral field emission diodes were fabricated by using separation by implantation of oxygen (SIMOX) wafer and their current-voltage characteristics (I-V) were analyzed. Applying conventional photolithography and local oxidation of silicon (LOGOS) process, we fabricated single-crystalline lateral silicon field emitters with very sharp cathode and anode tips and very short cathode to anode spacing ranging from 0.3 to 0.8 μm as well. Two different types of tips, tapered and wedge-shaped emitters, were typically formed according to oxidation time. The turn-on voltages for both types of diodes were as low as 22~25 V and the emission currents were as high as 6 μA/tip at voltages of 35~38 V. From the Fowler-Nordheim (FN) equation, field emitting area (A) and field enhancement factor (β) for both types of diodes were estimated to explain the low turn-on voltages and the high emission currents     

Field emission from metal-coated silicon tips

Microfabrication processes previously described by D. Stephani and J. Eibl (1989) were refined and used to fabricate silicon tips coated with layers of titanium, tantalum, or platinum using physical vapor deposition techniques. The emphasis was upon creating tips with a large ratio of length to diameter. The emission properties of various groupings of emitters thus formed were investigated using an accurately positioned counterelectrode. The counterelectrode was made of tungsten coated with nickel and had a well-defined tip geometry. Measurements were performed on individual groups of one, four, or nine field emitters. Fowler-Nordheim plots were made for a variety of coating materials, emitter-to-electrode spacings, and tip geometries. It is concluded that, for many applications, tip optimization should not be aimed solely at the achievement of high field strengths but that the emitting area should also be as large as possible     

Electron field emission from ZnO self-organized nanostructures and doped ZnO:Ga nanostructured films

Self-organized ZnO nanostructures were grown by thermal decomposition of metalorganic precursors as well as by carbothermal reduction process. Nanostructured undoped and gallium-doped ZnO nanostructured films were deposited by plasma-enhanced chemical vapor deposition from metalorganic compounds. Electron field emission follows Fowler-Nordheim equation. Efficient electron emission was obtained from self-organized nanostructures due to their geometric shape. Enhanced field emission from ZnO:Ga nanostructured films in comparison with undoped ZnO films is obliged to lowering work function at doping by gallium.     

Carrier transport mechanism in La-incorporated high-k dielectric/metal gate stack MOSFETs

In this paper, carrier transport mechanism of MOSFETs with HfLaSiON was analyzed. It was shown that gate current is consisted of Schottky emission, Frenkel-Poole (F-P) emission and Fowler-Nordheim (F-N) tunneling components. Schottky barrier height is calculated to be 0.829 eV from Schottky emission model. Fowler-Nordheim tunneling barrier height was 0.941 eV at high electric field regions and the trap energy level extracted using Frenkel-Poole emission model was 0.907 eV. From the deviation of weak temperature dependence for gate leakage current at low electric field region, TAT mechanism is also considered.