US 5,804,084 A · Use of chemical mechanical polishing in micromachining

Abstract

A process for removing topography effects during fabrication of micromachines. A sacrificial oxide layer is deposited over a level containing functional elements with etched valleys between the elements such that the sacrificial layer has sufficient thickness to fill the valleys and extend in thickness upwards to the extent that the lowest point on the upper surface of the oxide layer is at least as high as the top surface of the functional elements in the covered level. The sacrificial oxide layer is then polished down and planarized by chemical-mechanical polishing. Another layer of functional elements is then formed upon this new planarized surface.

Claims15

Dependent claims

A method of micromachining a multilayer micromachine comprising:

forming a level of mechanical structures (hereinafter the first level) above which at least one more level of mechanical structures is to be formed;
depositing at least one layer of sacrificial material onto the first level of mechanical structures to fill at least a portion of the voids between the underlying mechanical structures in at least one portion of the first level;
removing at least some of the sacrificial material above the mechanical structures in at least a portion of the first level by chemical mechanical polishing to form a first planar surface;
and
forming a second level of mechanical structures on the first planar surface to engage with mechanical structures below the second level.

2 more elements

Dependencies are inferred from the claim text.

Use of chemical mechanical polishing in micromachining

Life of this patent

Use of chemical mechanical polishing in micromachining

Life of this patent

Abstract

Claims15