Cw laser crystallization of glow discharge a-Si:H on glass substrates

Glow discharge hydrogenated amorphous Si films were crystallized using a cw Ar laser. The properties of the crystallized films were studied by optical and electron microscopy, electrical measurements and elastic recoil detection (ERD) analysis. In addition, a preferential plasma etching technique was used to determine the degree of crystallization. Large (>3 μm) high quality crystallites were induced above a threshold laser power of 100 W/cm by an explosive crystallization process. This was accompanied by the formation of bubbles and ejection of material from the crystallization centers. The sheet resistivity decreased by five to six orders of magnitude. Some 50–90% of the hydrogen remained in the films after laser annealing. A simple model shows that solid state diffusion accounts for the final hydrogen distribution in the laser annealed films. The use of this material for the fabrication of devices on glass substrates is discussed.     

Schottky barriers fabricated on glow discharge A-Si:H films deposited under bias

Hydrogenated amorphous silicon films were deposited in a three electrode dc glow discharge system under the substrate bias. The composition of the films, using infrared spectroscopy, has been investigated. The photovoltaic parameters of the fabricated Au and Pt Schottky barrier structures have been measured. The purpose of this study was to determine if polarization of the substrates influence the properties of the deposited a-Si:H films. At present with the EECS Department, University of Santa Clara, Santa Clara, California 95053. At present with the Eaton Corporation, Milwaukee, Wisconsin 53216.     

阻滞放电中的OGE特性

测量了阻滞放电中He、Ne、Xe的红外光电流谱,OGE的空间分布及其与电流、气压的依赖关系,指出它的放电噪声极低.     

Breakdown voltage of the surface glow discharge

Breakdown voltage is an important parameter of the surface glow discharge especially from the standpoint of practical applications. The experimental results of the breakdown voltage measurements for this type of discharge together with the results obtained from theoretical analysis are given. The presented model is based on the calculation of the electric field, trajectories of charged particles (which do not follow the flux lines) and finally on the testing of the condition for the self sustained discharge. The obtained theoretical results are in good agreement with the experimental ones     

Oxidation and stress relief in air at room temperature of amorphous silicon hydrogenated in a glow discharge

Glow-discharge-hydrogenated amorphous silicon (a-Si : H) was found to be oxidized in the following two ways after exposing to air at room temperature; first, thin oxide films grew uniformly on the a-Si : H, slowly with increase of exposure time; secondly, oxide with a columnar morphology grew rapidly with the increase of exposure time and the cross section of the columnar oxide was small. Mechanical stress caused by the differences of the thermal expansion coefficient and the crystallographical structure between the a-Si : H and substrates was relieved with the increase in the amount of the columnar oxide.     

Low-cost glow discharge tube microwave frequency sensor

Inexpensive commercial neon lamps are observed not only to sense the presence of low-power RF radiation levels, but also to determine the frequency of the incident radiation with relatively good accuracy.     

Effect of glow discharge on chromium thin-film resistance

The resistivity of thin vacuum-evaporated chromium films varies significantly after deposition. Glow-discharge treatment immediately after deposition slowly increases the sheet resistance, and improves its stability during exposure to air and subsequent heat aging. This treatment enables a stable chromium film to be obtained with a sheet resistivity above 400 ?/square.     

Effects of ionizing radiation on glow discharge detectors

Glow discharge detectors in the abnormal glow mode can be used as sensitive detectors of microwave and millimeter wave radiation even in the presence of very intense γ ionizing radiation fields where semiconductor devices cannot operate. In the subnormal glow mode, glow discharge detectors give promise of being able to monitor ionizing radiation fields so intense that the usual electronic detectors saturate.     

High-power pulsed electron beam from a glow discharge

A cold-cathode electron gun has been developed in which a pulsed discharge in gas at about 0.1 torr produces a focused beam. With a concave disc cathode 5cm in diameter, a pulsed input of 20kV and 2A in hydrogen gave a power density at the focus between 106 and 107 W/cm2.     

Recombination lasers in a flowing negative glow discharge

A fast gas flow through a negative glow plasma creates an afterglow region where supercooled electrons are separated from energetic beam electronsto produce a population inversion by collisional recombination. A report on spatially resolved electron temperature measurements of the afterglow plasma showing electron temperatures in the range of 750-1100 K under steady-state conditions is presented. A 4-cm-long flowing hollow cathode discharge was used to obtain CW (continuous wave) recombination laser oscillation in ArI. Collisional recombination of singly and doubly ionized metal vapor species in the same type of plasma also produced pulsed laser action in infrared lines of PbI, ZnI, PbII, and SnII. The addition of H₂ is demonstrated to significantly increase the laser output intensity     

微空心阴极放电作大体积辉光放电电子源的模拟研究

基于MATLAB与VC 混合语言，采用Monte Carlo模拟对高气压下亚毫米级微空心阴极放电(MHCD)在第三电极牵引下电子的运动过程进行了研究，计算出不同电压、不同的尺寸结构下，电子的空间分布和被牵引出MHCD的电子能量分布。从理论上分析了MHCD结构要求，以及电压等参量对出射电子的能量分布影响。     

Room-temperature lasing of CdS crystals in a glow discharge

A very compact device has been made for excitation of lasing in CdS at room temperature. A low-pressure glow discharge is produced by high-voltage pulses to pump the CdS crystal. The simple design required to confine the discharge and produce the necessary high density of electrons is described.     

A glow discharge for uniform charging of electrophotographic layers

This correspondence reports results of investigations concerning a glow discharge under normal pressure and temperature conditions. Because of its high current efficiency and its good charging uniformity, the glow discharge is well suited for electrophotographic devices (charging as well as discharging) and for contactless discharging of clear dielectric foils.     

Junction solar cells made with molecular beam glow discharge bombardment

The fabrication and characterization of silicon p-n junction solar cells with various glow discharge, unanalyzed, molecular implanted emitter regions is described. Total area simulated air mass one (AM1) power conversion efficiencies without AR coatings or back surface fields are at best 8.2% compared to 9.1% for conventionally implanted or POC1₃ thermally diffused cells on similar substrates. To achieve optimum performance, Q-switched ruby laser light was incorporated into the molecular implant annealing procedure. Conversion efficiencies greater than 8% were achieved with the four dopants BC1₃, PC1₃ AsF₃ and POC1₃. For similar processing, conversion efficiency with BF₃ implants was less than those of previous investigations, most likely due to poor crystalline regrowth of the heavily doped emitter regions. Cell quantum efficiency and mesa junction ideality are shown to be similar to those of conventional cells while molecular implant sheet resistance values varied, generally being directly related to the dopant molecular weight. Work submitted in partial fulfillment of Ph.D. in Electrical Engineering at the Univ. of Missouri, Columbia, MO 65211     

Electrical and interface properties of Au/DNA/n-Si organic-on-inorganic structures

The effect of the thickness and coverage rate of a DNA film on the electrical and interface properties of Au/DNA/n-Si organic-on-inorganic structures has been investigated. The thin film properties of the DNA deposited on n-Si wafer were characterized by atomic force microscopy. The effect of the thickness and coverage rate of the DNA layer was investigated by evaluating electrical parameters, such as the barrier height, ideality factor, series resistance, and interface state density. The thickness and coverage rate of the DNA layer significantly affects the electrical properties of the Au/DNA/n-Si organic-on-inorganic structures. The interface state density properties of the Au/DNA/n-Si diodes were determined by conductance technique. The results show that the interface state density decreases with decrease in both film thickness and coverage rate of the DNA in an acetate buffer, modifying the electronic parameters of the Au/DNA/n-Si diodes.     

Hydrogenation of HgCdTe epilayers on Si substrates using glow discharge plasma

Preliminary results of a study of the hydrogenation of HgCdTe epilayers grown by molecular beam epitaxy on Si substrates using a glow-discharge plasma are presented. The aim of the program is to employ H to passivate the detrimental opto-electronic effects of threading dislocations present in the HgCdTe epilayers. Secondary ion mass spectroscopy depth profiling has been performed to characterize ¹H and ²H incorporation. It has been found that H can be controllably incorporated in HgCdTe epilayers to levels in the 10¹⁴ cm⁻³ to 10¹⁸ cm⁻³ range while maintaining the sample at temperatures lower than 60°C. Profiles indicate that H accumulates in regions of known high defect density or in highly strained regions. Analysis of the H depth profile data indicates that the current density-time product is a good figure of merit to predict the H levels in the HgCdTe epilayer. There are progressive differences in the ¹H and ²H uptake efficiencies as a function of depth. Magneto-Hall measurements show consistently higher mobilities at low temperatures for majority carriers in hydrogenated samples.     

Low temperature brazing of chip inductors by abnormal glow discharge plasma

A novel method, by which Cu was deposited on ferrite ceramics with arc-added glow discharge as a precursory procedure and then brazing the ferrite ceramics with vacuum glow discharge, was investigated. This new method can effectively suppress interfacial diffusion and brazing joint oxidation as well as maintain good adhesion in the joint due to low deposition and brazing temperature, the vacuum atmosphere effect, and the cathode sputter-cleaning action of the abnormal glow discharge plasma. The influence of the brazing process parameters on electrical and magnetic properties of the chip inductors is discussed. The optimal deposition and brazing process parameters are presented. Scanning electron microscope line scanning confirms the brazing electrode joints and detected the interfacial diffusion between the joints and the ferrite ceramics.     

A self-consistent model for negative glow discharge lasers: thehollow cathode helium mercury laser

A model for negative glow metal-vapor ion lasers that self-consistently describes the dynamics of the negative glow and the cathode sheath regions of the discharge has been developed. The model computes the electron energy distribution and the population of relevant excited states in the negative glow self-consistently with the charged particles fluxes and electric field distribution in the cathode sheath. Its application to the study of the helium-mercury charge transfer ion laser is reported. The model accurately depicts the operation of a hollow cathode in the laboratory, where for a defined cathode geometry and material, the discharge characteristics are determined by the selected discharge voltage and the gas pressure. The laser output power calculated as a function of the discharge parameters is in good agreement with experimental measurements reported in the literature. The model can be modified to simulate other negative glow discharge lasers, such as electron-beam pumped CW ion lasers     

一种可获得均匀辉光放电的封离式直流横向激励气体放电结构的研究

找到了一种可用数百伏直流电源激励的封离式横向气体放电结构,充入CO_2工作气体进行实验,获得了较大体积的稳定的均匀辉光放电。从理论上估算了此种结构和传统的封离式结构中一定注入电功率下工作气体的最高温度,指出了降低该温度的途径。