Planarization method using anisotropic wet etching
AssigneeMacronix International Co., Ltd.
InventorsWen-Bin Tsai, Ching-Yu Chang, Chun-Pei Wu, Huei-Huang Chen, Samuel C. Pan
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Abstract
A planarization method using anisotropic etching can be applied to planarize an insulating layer with an uneven surface on a substrate. H2SO4, H3PO4, HF and H2O are mixed to form an etching solution. The substrate is placed into the etching solution to make the etching solution pass the surface of the insulating layer at a flow rate to etch the insulating layer. After a period of etching time, the insulating layer with a more planar surface can be obtained.
Claims14
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.
A planarization method using anisotropic wet etching, which can be applied on a substrate having an insulating layer thereon, the insulating layer having large trenches and small trenches therein, comprising:
- using an insulating material to form protrusions in the large trenches, wherein a distance between the neighboring protrusions is about the same as the width of the small trenches and a thickness of the protrusions is about the same as a depth of the large and 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 insulating layer and the protrusions at a flow rate to etch the insulating layer and the protrusions.
Dependencies are inferred from the claim text.