Patent ID: 6787056
Filing Date: 2004-09-07
Classification: H01L

Abstract:
A planarization method using anisotropic wet etching, which can be applied on a substrate having a first insulating layer thereon, the first insulating layer having large trenches and small trenches therein, comprising:conformably forming a second insulating layer on the first insulating layer, a thickness of the second insulating layer is about the same as a depth of the large and the small trenches; patterning the second insulating layer to form protrusions in the large trenches, a distance between the neighboring protrusions is about the same as the width of the small trenches; mixing H2SO4, H3PO4, HF and H2O to form an etching solution; and placing the substrate into the etching solution to make the etching solution pass the surface of the first and the second insulating layer at a flow rate to etch the first and the second insulating layer.