In semiconductor manufacturing processes, it is important that the SiO 2 isolation films around aluminum connection lines have flat surfaces in order to produce the multilayered connection lines used in high-density devices. In this paper, we analyzed transient changes, in the thickness distributions of a liquid-SOG (Spin-on-Glass) film on a two-dimensionally (2-D) grooved substrate during the evaporative shrinking process. The flow due to surface tension of the shrinking liquid film was calculated. Since the film is thin, a boundary layer approximation could be applied, and fourth-order differential equations of film thickness were solved using an iteration method. The viscosity and the shrinkage rate were assumed to be functions of the concentration of the solvent in the film. When the parameter of ratio [(surface tension)=f(viscosity)2(shrinking speed)g] is large and the width of the grooves is small, final surface undulations of the film are shallow. The effect of the centrifugal force was also analyzed.

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This paper reports on recent improvements in organic spin-on glass (SOG) planarization technology combined with etch-back process. A general rule has been established for SOG planarization mechanism that is suitable for every kind of wiring pattern distribution. This general rule, the volume constant rule, shows that the SOG volume in a certain projection length along the horizontal direction is constant and independent of the wiring width. Based on this rule, it is found that the SOG planarization process margin can be increased significantly by decreasing the plasma SiO, (= P-SiO,) layer thickness underneath the SOG layer.The characteristics of this newly developed organic SOG material have been investigated. This new organic SOG material developed by Hitachi Chemical Company, Ltd. (HSG-2209S-R7) has heat reflow capability that causes the movement of SOG on the wires to the space during the second baking; this results in improvements in local planarization and decrease in the SOG thickness on the wires.A six-level metallization test structure for a logic LSI has been successfully created using the optimized process conditions.

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In semiconductor manufacturing processes, it is important that the SiO2 isolation films around aluminum connection lines have flat surfaces in order to produce the multi-layered connection lines used in high-density devices. In this paper, we analyzed transient changes, in the thickness distributions of a liquid-SOG (Spin-on-Glass) film on a two-dimensional grooved substrate during the evaporative shrinking process. The flow due to surface tension of the shrinking liquid film was calculated. Since the film is thin, a boundary layer approximation could be applied, and fourth-order equations of film thickness were solved using an iteration method. The viscosity and the shrinkage rate were assumed to be functions of the concentration of the solvent in the film. When the parameter of [(surface tension) / {(shrinking speed) × (viscosity)}] is large and the width of the grooves is small, final surface undulations of the film are shallow. The effect of the centrifugal force was also analyzed.