Chemical vapor deposition processes are employed to fill high aspect ratio (typically at least 3:1), narrow width (typically 1.5 microns or less and even sub 0.15 micron) gaps with significantly reduced incidence of voids or weak spots. This deposition process involves the use of hydrogen as a process...http://www.google.com/patents/US6596654?utm_source=gb-gplus-sharePatent US6596654 - Gap fill for high aspect ratio structures
