多孔硅场致电子发射

研究了多孔硅冷阴极的场致电子发射特性，实验表明采用电化学阳极腐蚀、氧化、蒸电极等工艺可以制备一种平面薄膜型多孔硅冷阴极。在超高真空环境下测量了多孔硅冷阴极的电子发射特性。     

可印制碳纳米管冷阴极中碳纳米管含量的优化

采用丝网印刷法制备了不同碳纳米管含量的冷阴极.研究了不同碳纳米管含量的冷阴极的场发射特性与其微结构和电学特性的关系.实验发现,碳纳米管冷阴极的导电性和场发射特性受碳纳米管含量影响,具有适当的碳纳米管含量的冷阴极的场发射特性最佳.     

多孔硅微结构与场发射性能研究

采用阳极氧化及阴极还原表面处理技术制备性能稳定的纳米多孔硅薄膜.用原子力显微镜(AFM)表征多孔硅的表面形貌,用扫描电子显微镜(SEM)表征多孔硅的横截面结构.采用场发射测试装置研究了阳极氧化腐蚀时间及等离子表面处理对多孔硅场发射性能影响.结果表明,阳极氧化腐蚀时间越长,所得多孔硅场发射性能越好,相对应的开启电压越低,电流密度越大;等离子处理可有效提高场发射性能,等离子处理后的多孔硅薄膜作为阴极发射材料具有极大的潜能.     

碳纳米带的合成及场致电子发射

介绍了液相合成的碳纳米带的场致电子发射特性，探索其在场发射中的应用。碳纳米带的合成采用电化学液相合成的方法在硅衬底上制备而成。通过扫描电镜和Raman光谱对碳纳米带的结构进行了分析。场发射特性测试结果表明，碳纳米带膜的场发射阈值电场为2．5V/μm。研究表明碳纳米带具有一些独到的特点，也非常适合场发射显示用冷阴极的制备。研究纳米石墨带薄膜的场发射特性对其在场发射显示器件和其他真空微电子器件中的应用有重要的意义。     

多孔硅衬底微波CVD金刚石薄膜的制备及其场电子发射

研究了多孔硅衬底微波CVD金刚石薄膜的制备工艺及其场电子发射特性.以多孔硅作为生长金刚石突起阵列的模板,生长出带多微尖的微晶金刚石晶粒,使场电子发射阈值下降(＜1V/μm),发射电流增大(＞90mA/cm2),场发射性能稳定,并对这种场发射特性做出了理论解释.     

多孔硅衬底微波CVD金刚石薄膜的制备及其场电子发射

研究了多孔硅衬底微波CVD金刚石薄膜的制备工艺及其场电子发射特性.以多孔硅作为生长金刚石突起阵列的模板,生长出带多微尖的微晶金刚石晶粒,使场电子发射阈值下降(<1V/ μm) ,发射电流增大(>90 m A/ cm2 ) ,场发射性能稳定,并对这种场发射特性做出了理论解释.     

光电材料多孔硅的多孔度理论计算方程

在制备多孔硅材料时,多孔硅的多孔度和厚度与电解电流强度、电解时间以及氢氟酸的浓度有关.如果氢氟酸的浓度保持不变,通过改变电解时间和电解电流强度就可以得到所需多孔硅的多孔度及厚度.但现在一般都通过测量设备来重复测量多孔硅的多孔度及厚度,特别是多层多孔硅,很难严格控制其厚度.为此,通过对多孔硅中载流子运动的研究,结合BET方程中的SBET定义,推导出多孔硅的多孔度、电解速度和电解电流强度之间的关系表达式.通过该理论公式,就可以保证精确得到多孔硅的多孔度及厚度.该理论公式得到了实验的验证.     

光电材料多孔硅的多孔度理论计算方程

在制备多孔硅材料时 ,多孔硅的多孔度和厚度与电解电流强度、电解时间以及氢氟酸的浓度有关 .如果氢氟酸的浓度保持不变 ,通过改变电解时间和电解电流强度就可以得到所需多孔硅的多孔度及厚度 .但现在一般都通过测量设备来重复测量多孔硅的多孔度及厚度 ,特别是多层多孔硅 ,很难严格控制其厚度 .为此 ,通过对多孔硅中载流子运动的研究 ,结合 BET方程中的 SBET定义 ,推导出多孔硅的多孔度、电解速度和电解电流强度之间的关系表达式 .通过该理论公式 ,就可以保证精确得到多孔硅的多孔度及厚度 .该理论公式得到了实验的验证     

一维纳米硅光子晶体的制备与优化

采用双槽电化学腐蚀法制备了纳米多孔硅,主要研究了腐蚀时间和腐蚀电流对重掺杂p型(100)硅衬底上制备的多孔硅层有效光学厚度的影响,采用U-4100光谱仪、场发射扫描电子显微镜(FESEM)技术对所制备的多孔硅光子晶体的结构和有效光学厚度进行了分析表征。研究结果表明,通过合理地选择腐蚀时间和腐蚀电流,可以比较精确地制备特定有效光学厚度的多孔硅薄膜,此方法可广泛应用于纳米多孔硅光子晶体的制备中。     

硅微尖锥冷阴极微加工及其场发射器件物理

片上集成驱动控制电极的硅微尖锥是一类重要的场致电子发射阴极(冷阴极),具有驱动电压低、集成度高、加工流程与集成电路工艺兼容的特点,在微型化真空电子器件上具有应用潜力。本文介绍片上集成硅微尖锥冷阴极关键微纳加工方法及原理,分析硅微尖锥冷阴极场发射器件物理,展望硅微尖锥冷阴极的应用前景。     

FIPOS (Full Isolation by Porous Oxidized Silicon) technology and its application to LSI's

Processing steps of FIPOS (Full Isolation by Porous Oxidized Silicon) technology and its application to LSI's are presented, FIPOS technology realizes a silicon-on-insulator structure, utilizing thick porous oxidized silicon and donors produced by proton implantation. New processing steps are proposed which provides small surface step and are suitable for LSI fabrication. Formation conditions of thick porous oxidized silicon are established by density control technique for porous silicon using a newly developed anodization system. CMOS devices are fabricated in isolated silicon layers and it is shown that the characteristics of n-channel and p-channel MOSFETS's are sufficient for application to CMOS LSI's. A FIPOS/CMOS logic array with 1.3K gate is successfully fabricated, which shows a higher speed and lower power dissipation than the gates fabricated by bulk CMOS technology. These results indicate that FIPOS technology is very useful for realizing high-performance CMOS LSI's.     

多孔硅场发射阴极研究进展

多孔硅(Porous Silicon,PS)平面阴极的场发射电子能量高、发散角小、对真空度不敏感、响应快,尤其适合用作场发射显示的电子源,基于PS阴极的无放电气体激发发光也为新型环保的高效平面光源技术带来了希望。本文介绍了PS阴极的电子发射原理及其研究进展,展望了其在显示技术、无放电气体激发发光技术、金属线沉积、电子束刻蚀以及其他领域的应用前景。     

Fabrication,characterization, and analysis of photodetectors metal-porous silicon with different geometry and thickness of the porous silicon layer

Porous silicon photodetectors obtained by electrochemical etching of p-type non-polished crystalline silicon were studied. A metal-porous silicon structure was used to obtain the rectifying behavior. The geometry of the metal layer deposited by thermal evaporation on the porous zone was modified with different masks fabricated using a photolithographic method. The samples obtained under different anodization conditions were characterized by PL. The sample that showed the best intensity in photoluminescence, centered on 675 nm, was selected and five samples obtained under these conditions were prepared to compare the difference in the photoresponse because of the geometry of the evaporated metal layer. The responsivities obtained show us an important difference between the devices and allow us to propose a specific geometrical pattern to obtain a better response in this kind of devices.     

用于硅衬底隔离的选择性多孔硅厚膜的制备

在硅衬底上形成高阻隔离层对于提高硅基射频电路的性能具有重要意义。采用多孔硅厚膜作为隔离层 ,能够极大地降低衬底高频损耗。本文对n+型硅衬底上选择性多孔硅厚膜的制备进行了研究。通过在阳极氧化反应中采用不同的HF溶液的浓度、电流密度和反应时间来控制多孔硅的膜厚、孔隙度等特性。有效地减少了多孔硅的龟裂失效 ,得到的多孔硅最大膜厚为 72 μm。并测量了多孔硅的生长速率与表面形貌     

纳米多孔硅的场致电子发射性能研究

对采用阳极氧化法及阴极还原表面处理技术制备的性能稳定的纳米多孔硅,用原子力显微镜(AFM)表征了其微观结构,多孔硅颗粒粒径在30 nm左右.室温条件下测试了多孔硅场电子发射的特性,结果表明,多孔硅具有很好的场致发光性能,在5 V/μm的电场下就可以产生场发射电流.多孔硅的开启电压在1 000 V左右,发射电流随着电压的增大而不断增大,发射电压在2 000 V以上.

Abstract：

Nanoscale porous silicon (PS) was prepared by anodic oxidation, cathode reduction and surface treatment technique. The porous silicon particles with the average diameter of about 30 nm were obtained by characterizing their microstructure with atomic force microscope (AFM). Electron field emission characteristics of porous silicon were investigated at room temperature. The resuhs demonstrate that porous silicon has favorable electroluminescence properties, and the field emission current can be generated only under the electric field of 5 V/ μm. And the turn - on voltage is about 1 000 V. With the increase of the offered voltage, the emission current is enhanced and the emission voltage is over 2 000 V.     

Current-induced light emission from a porous silicon device

Experiments with light-emitting porous silicon (LEPOS) are described. The porous silicon was made from n-type silicon by anodization in an electrolytic cell by HF with an applied electrical current. Visible light emission was achieved by irradiation with ultraviolet light. Visible electroluminescence (EL) was achieved by applying a DC or AC voltage to a solid-state contact on top of the porous layer. Optical spectra from both experiments are shown     

Photoelectric properties of porous GaN/SiC heterostructures

The origin of photoconductivity in porous structures formed by anodization of GaN/SiC heterostructures has been studied. It is shown by comparing the photoelectric, optical, electrical, and structural properties of untreated and anodized heterostructures that this effect is due to the presence of charged states at the interface between GaN and SiC that are specific to the anodization conditions.     

磁控溅射碳化硅膜的制备及其光致发光特性

采用磁控溅射方法制备了SiC薄膜,然后采用电化学方法将其腐蚀后获得具有纳米结构的多孔碳化硅.样品的PL谱表明,未经电化学腐蚀的薄膜能发出弱的紫光,峰值在392 nm;当样品用电化学的方法腐蚀后,获得位于376 nm的紫外光发射,且发光强度得到极大提高.     

Combustion and explosion of nanostructured silicon in microsystem devices

Combustion and explosion in layers of nanostructured porous silicon has been studied in relation to the layer thickness and duration of sample storage after electrochemical anodization. The amount of hydrogen adsorbed on the surface of porous silicon after anodic treatment is evaluated. The amount of hydrogen accu-mulated in porous silicon is 4 wt %. Prototype microsystem devices employing the energy of the processes studied have been developed and fabricated. The combustion of porous silicon can be used as an energy source for silicon microactuators and the microexplosion can be employed both in self-destructing silicon chips and for dividing silicon wafers into separate crystals.