Space and phase resolved ion energy and angular distributions in single- and dual-frequency capacitively coupled plasmas
The control of ion energy and angular distributions (IEADs) is critically important for anisotropic etching or deposition in microelectronic fabrication processes. With single frequency capacitively coupled plasmas (CCPs), the narrowing in angle and spread in energy of ions as they cross the sheath are definable functions of frequency, sheath width, and mean free path. With increases in wafer size, single frequency CCPs are finding difficulty in meeting the requirement of simultaneously controlling plasma densities, ion fluxes, and ion energies. Dual-frequency CCPs are being investigated to provide this flexible control. The high frequency (HF) is intended to control the plasma density and ion fluxes, while the ion energies are intended to be controlled by the low frequency (LF). However, recent research has shown that the LF can also influence the magnitude of ion fluxes and that IEADs are determined by both frequencies. Hence, separate control of fluxes and IEADs is complex. In this paper, results from a two-dimensional computational investigation of Ar/O2 plasma properties in an industrial reactor are discussed. The IEADs are tracked as a function of height above the substrate and phase within the rf cycles from the bulk plasma to the presheath and through the sheath with the goal of providing insights to this complexity. Comparison is made to laser-induced fluorescence experiments. The authors found that the ratios of HF/LF voltage and driving frequency are critical parameters in determining the shape of the IEADs, both during the transit of the ion through the sheath and when ions are incident onto the substrate. To the degree that contributions from the HF can modify plasma density, sheath potential, and sheath thickness, this may provide additional control for the IEADs.
Yiting Zhang, Mark J. Kushner, Nathaniel Moore, Patrick Pribyl, and Walter Gekelman
Silver nanoparticles have been obtained by photoreduction from solutions during the last two decades, but the growth of differently structured silver nanoparticles directly onto transparent substrates has not been a major area of research. An analysis of silver deposition on glass substrate ... mehr
The authors present a focused ion beam lithography (IBL) instrument and its extension toward using different ion species beyond gallium. The base instrument utilizes a lithography architecture and an ion source and column dedicated to nanofabrication. This includes large area navigation and ... mehr
Substrate conformal imprint lithography (SCIL) is an innovative soft lithography method for the transfer of large area nanostructures. This technology was originally invented by Philips Research. With the implementation of the SCIL process on mask aligners, the standard alignment options of ... mehr