Experimental Investigation Of Discharge Characteristics In Cylindrical Radio-Frequency Inductively Coupled Plasma

Inductively coupled plasma ?ICP? source has been widely used in industrial-materials processing for chips etching and thin films deposition due to its advantages, such as that, ICP can obtain high density, large area and uniform plasma with low pressure. The investigation of Ar/O₂ mixture gases discharge has been done a lot, but the research of radial spatial resolution characteristics of cylindrical ICP discharge is not enough. Therefore, further investigation is necessary. On the other hand, the discharge parameters has a great influence on discharge characteristics, especially for the uniformity of plasma which is very important in the industry application. The method of Langmuir probe and the optical emission spectroscopy are employed to study the parameters ?power, pressure, O₂ content? influences on the discharge characteristics of ICP.The first chapter, introduces the concept, properties, and applications of plasma, as well as some kinds of low-temperature plasma source used in industry, otherwise the current research status of inductively coupled plasma is shown.The second chapter, briefly introduces the ICP source equipment and diagnostic devices: Z-Scan, Langmuir probe and the spectral diagnosis system.In chapter 3, Ar plasma is studied. The results show that the electron density increase with the power is increased, while decrease with the increasing pressure; The plasma potential and electron temperature decrease with the increase of pressure; The electron temperature almost has nothing to do with power. The plasma potential decrease with the increase of power at low-power, and almost change little at high-power. In low-pressure and low-power, the electron energy probability distribution function shows two temperature distribution, with the increase of power and pressure, it tends to the Druyvesteyn distribution gradually. The line intensity 750.4 nm and 811.5 nm of Ar, are proportionally increased with increasing power, and decreased with increasing pressure. In the radial direction, the line intensity from the center to the wall is decreased gradually.In the fourth chapter, the Ar-O₂ plasma is studied. The results show that electron density is increased with increasing power, decreased with increasing pressure and O₂ content; the line intensity of Ar and O atom increased with increasing power, decreased with increasing pressure and O₂ content.In the fifth chapter, the O₂ plasma is studied. The results show that line intensity of O atom 777.4 nm and 844.6 nm are.proportionally increased with increasing power, and decreased with increasing pressure. In the radial direction, the line intensity from the center to the wall is decreased gradually.