Construction Of ECR Plasma/Ion Beam Platform And Regulating Of Silicon-Based Nanostructures Growth

High density plasmas have been significantly applied in plasma processes including ion implantation, plasma etching and deposition. Microwave electron cyclotron resonance (ECR) plasma is one of the typical high density plasmas. Until now, many ECR plasma sources and ion sources, which possess such advantages as simple construction, working stably and long life, have been developed. One-dimension (1D) silicon-based nanomaterial is one of the fundamental components of nanoelectronic and photoelectronic devices. Considerable attention is attracted on controllable growth of1D nanostructures, including structure and properties. The highly ordered NWs and controlled doping are especially expected.In this thesis, studies on construction of high density ECR plasma device and application in growth of silicon-based nanomaterials are accomplished. The high density ECR plasma source/ion source device is developed and the parameters of plasma beam and ion beam are investigated. Regulating research on fabrication of silicon-based nanomaterails using ECR/RF plasmas is carried out. At last, preliminary study on the deposition of Co film in high density ECR plasma is discussed, which provides significant support for the further work of compound magnetic materials.As the high density ECR plasma source/ion source device is built, the Ar and H2plasma parameters are diagnosed by a dual-probe system. In normal situations, the electron density of Ar plasma is kept at the magnitude of1012cm-3, in which it goes to4.5×1012cm-3with a pressure of4Pa and microwave power of1800W. Meanwhile, the density of H2plasma is inferior to Ar with a magnitude. The discharge mode and variation of plasma parameters are also studied by changing the beam hole downstream the resonance region. It is found that the density of both Ar and H2plasmas reduce with the decreasing beam hole, but the turning point of discharge mode of H2plasma changes and becomes only one turning point. On the base of the high density ECR plasma source, we design multi-holes and single-hole ion sources and preliminary measure the ion flux. The flux of multi-holes ion source is at the magnitude of1020m-2s-1, while the flux of single-hole source goes to1021m-2s-1.Silicon oxide films were deposited in RF-biased ECR plasma using a mixture of HMDSO and oxygen as source gases. It is found that both the deposition rate and chemical bonds of films are significantly affected by the RF bias. The deposition rate is slightly increased when a low dc self-bias is applied, and reduced with the self-bias increasing due to strengthened ion bombardment. The ratios of O and Si in the films deposited under the bias frequency of400kHz are above2:1, nearly the same as that under13.56MHz. But the content of carbon under400kHz bias is much higher than that under13.56MHz. The cause of those is that the application of the high frequency bias of13.56MHz not only strengthens ion bombardment on the material surface, but also induces the variations of the bulk plasmas including the increase of O atom density, while the main effect of the bias of400kHz is only to strengthen ion bombardment.The difference between the applications of ECR and RF plasmas in synthesis of silicon nanowires (NWs) is investigated, using5%SiH4-He as vapor source. The NWs grown in low pressure ECR plasma are short, needle-shaped and porous, while the NWs fabricated in CCP plasma are long, uniform and heavy. Both of two kinds of NW are composed by amounts of crystalline nanoparticles and amorphous component.Formation of Cu-doped SiOxCy nanostructures has been studied by using (HMDSO)/H2/Ar RF plasma, where a copper tube was utilized as power electrode to generate plasma jet. Tree-like nanostructures were obtained at low concentration of HMDSO. The vertical gas flow induced the initial vertical growth of NWs, and spherical structures on sidewalls of the bended NWs were observed, which were attributed to secondary catalyzing due to copper from the ambience. However, the fragments with big mass were too many to synthesize nanostructure at high concentration of HMDSO. More Cu particles were transported to the substrate while an RF bias was applied to the substrate, which restrained the NWs growth catalyzed by Au and resulted in the formation of acaleph-like nanostructures,Feasibility of the deposition of cobalt film using high density ECR plasma is discussed, which provides support for the further research on the doping of Co film and study of the magnetic properties of compound materials. The Co film deposited in RF-biased plasma with temperature of400K exhibits excellent magnetic properties which can be compared with single-crystalline film, while the film fabricated in DC-biased plasma shows various crystal orientation and evident anisotropy.