Research Of Beams Based On High-density Plasmas

High-density plasma and ion beams are widely applied in plasma processing such as material synthesis and surface treatment. The characteristics of beams, which depend extremely on the discharge modes and discharge conditions, are crucial to the industrial applications. Experimental studies of kinetic properties of plasma beams are important to understand the mechanism for plasma processes and the optimization of various processing parameters. In this thesis, basic researches on the characteristics of beams based on two typical types of high-density plasmas, microwave electron cyclotron resonance (ECR) plasma and inductively coupled plasma (ICP), are carried out. Preliminary studies on material deposition by high-density plasma beams are also accomplished.Ion properties are investigated in both plasma beam and ion beam based on ECR discharge, and experimental work on the interaction between beams and material are carried out.Firstly, the mass and energy spectra of ions in ECR Ar/N2 plasma are diagnosed by a Hiden EQP analyzer as a function of the mixture compositions, microwave power and pressure. The ion energy distribution functions of Ar+and N2+, dominant ions detected in plasma, exhibit complicated evolutions of peak structures the simultaneous drift of energy peaks with varying the discharge conditions, transforming among the cases of unimodal, bimodal and trimodal distributions. It is suggested that the distributed ionization and the charge-exchange reactions between ions and neutrals, involved with the molecular structures of gas, are responsible for the evolutions.Ion components and IEDFs are compared between ECR hydrogen plasma and ion beams. H+, H2+ and H3+ are detected in both beams, while H2+ has the maximum proportion in plasma beam and H3+ is the main ion in ion beam. It is found that the addition of microwave power and extractor bias respectively for plasma beam and ion beam will cause the variation of relative concentration of these ions. The width of IEDF will also broaden, and more ions of higher energies are produced. These changes are related to the transformation between different ions and the acceleration of spacial electrical field.Structure information of tungsten after irradiation of ECR argon ion beam are obtained, involved with the effect of several parameters, such as the extraction voltage, the irradiation time, the temperature of substrate and the incident angles of beams. After exposing to the ion beam, unevenness turns up on the surface of tungsten slugs, showing that physical sputtering is the main mechanism in the interaction between ion beams and tungsten. The unevenness will be aggravated when adding the impinging energy and impinging time, but shows little independence on the temperature of substrate. Additionally, the effect of physical sputtering is most obvious in the case of vertical incidence of ions.Iron nitride thin film is deposited by using ECR A1/N2 plasma beam. The compound of film is failed under the conditions of pure nitrogen discharge or low bias voltages on the sputtering target. As the process that sputtered atoms broken away from the target and transported into plasma are quite relied on the energy of impinging ion, the absent of film is due to slow sputtering yields when ion energies are small. The addition of argon into nitrogen and the increase of bias voltage can both enhance the impinging of ions on the surface of sputtering target, which promotes the production of sputtered atoms. The film obtained are multiphase and of favorable magnetic properties.As for ICP discharge, we have investigated on the microplasma jets driven by a 150 MHz very-high-frequency power supply at atmospheric pressure. A micrioplasma of 3 cm in length and about 3 mm in diameter can be produced at 90 W power applied with gas temperatures above one thousand degree centigrade. The jet length rises first, and then decreases by increasing gas flow rate, showing a transition from laminar flow to turbulence. The jet length also increases by enhancing applied power, but then keeps a maximum value with further enhanced power, which is attributed to the attainment of equilibrium between the energy absorption and losses during the transport process in plasma. The plasma can be operated both in "cold" status near room temperature and "hot" status exceeding temperature of several hundred degrees Kelvin by second ignition of an external trigger. The change of status are accompanied with the variation of plasma morphology, jet length, coil current and supply power, showing an E-H mode transition which attributes to the saltation of plasma impedance and conductance by the second ignition. This leads to the sudden change of plasma density and further affects the absorption efficiency of power.By using the microjet, copper spherical cap and column were manufactured, respectively. Particles obtained on the substrate surface by scanning electron microscopy (SEM) are far smaller than the source powders, indicating a melting process of copper powders in plasma, as well as high gas temperature exceeding the melting point of copper. The weak peak of Cu2+1O is present besides strong copper diffraction lines in X-ray diffraction pattern, suggesting the weak oxidation happened during rapid manufacturing.