Silica‐Based Oxide Systems: I . Experimental and Calculated Phase Equilibria in Silicon, Boron, Phosphorus, Germanium, and Arsenic Oxide Mixtures

Relations between the glass transition, the flow, and the liquidus temperatures were studied in order to determine compositions of silica‐rich oxide materials for planarization layers in very large scale integrated technology. Thus, the , , , , and binary phase diagrams involved were experimentally determined. These binary diagrams were calculated using a polynomial description of the Gibbs free enthalpy of mixing for liquid phases and solid solutions. Ternary and quaternary phase diagrams were then computed in the silica‐rich region, giving the liquidus temperatures for selected mixtures. In determining the lowest liquidus temperatures, compositions in the and systems have been proposed to obtain low reflow temperatures.