Search

Plasma source ion implantation (PSII) is a technique for modifying stafaces that places the object to he modified directly into a plasma and then negatively pulse biases the object so as to implant positive ions. If the voltage is high enough, X-rays can he generated by electrons that are also accelerated by the pulse. This work describes techniques for imaging and characterizing the X-rays A pinhole camera was used to image the X-rays being emitted as electrons collided with surfaces in the chamber. The images show that X-rays are generated at the chamber walls and near the target. The time dependence of these X-rays during each pulse was examined using a PIN diode X-ray detector. Then, using another X-ray sensor and pulseheight analyzer, the spectra of the emitted X-rays was determined. The object is to relate the X-ray intensity and spectrum to the temporal and spatial values of the implantation dose so that it may he used as a process monitor and a control sensor.

An in situsingle point two-color laser interferometer is used to monitor in real-time the thickness of thin transparent films during processing. The instantaneous change of film thickness is determined by comparing the measured laser reflection interference to that calculated by a model. The etch or deposition rates of the film are determined within 1–2 seconds. The film thickness is also determined in real-time from the phase difference of the reflected laser intensity between the two laser colors. Use of two-color laser interferometry improves the accuracy of the calculated etch or growth rates of the film considerably. Moreover, the two colors provide a clear distinction between film etching and deposition, which may often occur during the same process, and can not be determined by a single color interferometer. The uniformity of the film's etch or deposition rates across the substrate is monitored by an in situfull-wafer image interferometer. The combined use of these two sensors provide instantaneous information of the film thickness, etch or growth rates, as well as time averaged uniformity of the process rates. This diagnostic setup is very useful for process development and monitoring, which is also suitable for manufacturing environment, and can be used for real-time process control.

Plasma-aided manufacturing is used for producing new materials with unusual and superior properties, for developing new chemical compounds and processes, for machining, and for altering and refining materials and surfaces. Plasma-aided manufacturing has direct applications to semiconductor fabrication, materials synthesis, welding, lighting, polymers, anti-corrosion coatings, machine tools, metallurgy, electrical and electronics devices, hazardous waste removal, high performance ceramics, and many other items in both the high-technology and the more traditional industries in the United States.

The axial distribution of the electrostatic potentials ofan electron-cyclotron resonance (ECR) processing plasma confined in a do magnetic mirror geometry was characterized. The potential profiles far argon and helium at 8.0x 10-4 and 4.0 × 10-4 Torr were measured using electron emissive probes. The experimental measurements were then compared with the predictions of a one-dimensional, electrostatic, particle-in-cell computer code which runs on a personal computer. The potential profiles as predicted by the code showed good agreement with the experimental measurements.

A plasma source has been designed so as to inject plasma directly into a Fourier transform mass spectrometer analysis cell. The source is a small radio-frequency cavity in which gas is ionized with RF. The source is coupled to the analysis cell through a small orifice. Argon irons from an argon plasma produced in the source have been injected, trapped and heated (excited), and detected in the analysis cell.

The effects of base pressure, etch pressure, gas flow rates of HCl, Cl2, and argon, hexode temperature, DC self-bias, initial polysilicon thickness, and percent of overetch on the etch performance of polysilicon are examined. Statistical design of the experiments provided linear and quadratic models of the etch performance in terms of the aforementioned variables. These models were used to determine the relative importance of each process variable on the etch performance. Optical emission data were utilized as a means of endpoint detection and as a monitor of etch activity. The results indicate that the etch performance is more responsive to variations in physical mechanisms as opposed to chemical processes within the variable ranges used in these experiments.

The relative fluorine-atomic concentrations and the abundance of CFxfunctionalities from CF4- and C6F6-RF-plasma treated polypropylene (PP) film surfaces were evaluated. Survey and high resolution (HR) ESCA data indicate that intense surface fluorination can be carried out, from both fluorine precursors, under relatively low power and treatment time conditions. However, it was found that the stability (under open laboratory conditions and under various solvent and temperature environments) of plasma implanted fluorine based groups significantly depend on the nature of plasma gases involved. Simulation of plasma induced molecular fragmentation, at different electron energy MS conditions, indicates the presence of a much higher fluorine atom concentration from a CF4-plasma in comparison to a C6F6-plasma. It is suggested that fluorine atom mediated fragmentation of macromolecular backbones is probably responsible for the erosion of plasma fluorinated surfaces, rather than thermal motion induced burying processes.

Polypropylene fabrics samples were surface functionalized under Ar and O2RF plasma conditions. Survey and high resolution photoelectron spectroscopy and attenuated total reflectance FTIR comparative evaluation of virgin and plasma treated substrat surfaces, and their pentafluorophenyl hydrazine-derivatized correspondents, indicate that both Ar and O2-discharge treated PP surfaces undergo intense oxidation. C=O, O−C=O, and C−O linkages were identified on both inert and reactive gas plasma exposed surfaces. It was found that the relative surface atomic concentrations and the relative ratios of newly created functionalities are controlled by the external plasma parameters (RF power and treatment time). The oxidation of Ar-plasma treated surfaces has been related toex situpost plasma mechanisms. Dynamic contact angle measurements from unmodified and plasma exposed substrates demonstrated the presence of increased surface polarity, and its dependence on plasma parameters. AFM evaluations of plasma treated samples indicate the presence of rough surface morphologies.