Chemical-mechanical polishing processes of planarizing insulating layers

A semiconductor processing method of providing and planarizing an insulating layer on a semiconductor wafer comprising the following sequential steps:

• providing a conformal layer of insulating material to a first thickness over a semiconductor wafer having non-planar topography;
• providing a blanketing chemical-mechanical polishing protective layer over the conformal layer to a second thickness, the protective layer being of different composition than the conformal layer, the blanketing protective layer having an outermost surface;
• and
• chemical-mechanical polishing the protective layer and conformal layer in at least two chemical-mechanical polishing steps using first and second respective chemical-mechanical polishing slurries, the first chemical-mechanical polishing slurry and step being conducted through the outermost surface of the protective layer and removing outermost portions of the protective layer in a manner which is substantially selective to the underlying conformal layer to outwardly expose conformal layer material in high topographical areas by such first chemical mechanical polishing step, the second chemical-mechanical polishing step and slurry removing the conformal layer material at a faster rate than the protective layer material, and continuing the second step chemical-mechanical polishing .through the protective layer and the conformal layer until all protective layer material is removed, the protective layer upon outward exposure of conformal layer material in high topographical areas restricting material removal from low topographical areas during such second chemical-mechanical polishing step.

A semiconductor processing method of providing and planarizing an insulating layer on a semiconductor wafer comprising the following sequential steps:

• providing a conformal layer of insulating material to a first thickness over a semiconductor wafer having non-planar topography;
• providing a blanketing chemical-mechanical polishing protective layer over the conformal layer to a second thickness, the protective layer being of different composition than the conformal layer, the blanketing protective layer having an outermost surface;
• and
• chemical-mechanical polishing the protective layer and conformal layer in at least three chemical-mechanical polishing steps using first and second respective chemical-mechanical polishing slurries, the first chemical-mechanical polishing slurry and step being conducted through the outermost surface of the protective layer and removing outermost portions of the protective layer in a manner which is substantially selective to the underlying conformal layer to outwardly expose conformal layer material in high topographical areas by such first chemical mechanical polishing step, the second chemical-mechanical polishing step and slurry removing the conformal layer material at a faster rate than the protective layer material, the protective layer upon outward exposure of conformal layer material in high topographical areas restricting material removal from low topographical areas during such second chemical-mechanical polishing step, the third chemical-mechanical polishing step using the first slurry and being conducted to remove any remaining protective layer material.