Vincent M. Donnelly

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Previously published applications of optical emission spectroscopy as a quantitative plasma diagnostic technique are reviewed. By adding traces of rare gases to the plasma, electron temperatures (Te) and relative electron and ion densities can be determined from electron impact-induced optical emission. Excitation from both the ground state and metastable(More)
We report a radically different approach to the versatile fabrication of nanometer-scale preselected patterns over large areas. Standard lithography, thin film deposition, and etching are used to fabricate arrays of ion-focusing microlenses (e.g., small round holes through a metal/insulator structure) on a substrate such as a silicon wafer. The substrate is(More)
The absolute densities of positive ions ~Cl2 1 and Cl! are obtained over a 2–20 mTorr pressure range and 5–1000 W input radio-frequency rf power range in a transformer-coupled Cl2 plasma. The relative number density of Cl2 1 is measured by laser-induced fluorescence. These laser-induced fluorescence data are calibrated by Langmuir-probe measurements of(More)
A Particle-in-Cell simulation with Monte Carlo Collisions (PIC-MCC) was conducted of the application of tailored DC voltage steps on an electrode, during the afterglow of a capacitively-coupled pulsed-plasma argon discharge, to control the energy of ions incident on the counter-electrode. Staircase voltage waveforms with selected amplitudes and durations(More)
Measurements of electron temperatures Te and electron energy distribution functions EEDFs in a dual frequency capacitively coupled etcher were performed by using trace rare gas optical emission spectroscopy TRG-OES . The parallel plate etcher was powered by a high frequency 60 MHz “source” top electrode and a low frequency 13.56 MHz “substrate” bottom(More)
The authors report a new, important phenomenon: photo-assisted etching of p-type Si in chlorinecontaining plasmas. This mechanism was discovered in mostly Ar plasmas with a few percent added Cl2, but was found to be even more important in pure Cl2 plasmas. Nearly monoenergetic ion energy distributions (IEDs) were obtained by applying a synchronous dc bias(More)
In plasma materials processing there is a continuing need to control the ion energy distributions (IEDs) on surfaces to increasing precision. A recent development in obtaining this control in inductively coupled plasmas (ICPs) is the use of a boundary electrode in which a continuous or pulsed dc bias is applied to the plasma. The characteristics of IEDs(More)
Ion energy distributions (IEDs) on a grounded substrate in a Faraday-shielded argon inductively coupled plasma were measured with a retarding field energy analyzer. A Langmuir probe was also used to measure spaceand time-resolved plasma parameters. IEDs and plasma parameters were studied with continuous or pulsed positive dc bias voltage on a ‘boundary(More)
ion reactions of H, which enhanced decomposition of higher hydrides into monohydrides. Parsons et al. grew thin layers of a-Si:H in a SiH4 CCP, then exposed the film to a H2 plasma in the same reactor. No deposits were observed when the H2 exposure time exceeded 2.8 times the deposition time. Eighteen SiH4/H2 cycles were required to initiate film growth on(More)