Differential trench open process
AssigneeInfineon Technologies North America Corp.
InventorBrian S. Lee
Life of this patent
Estimating the term…
Abstract
In accordance with the invention, a method for opening holes for semiconductor fabrication includes the steps of providing a pad stack on a substrate, forming a hard mask layer on the pad stack, the hard mask layer selectively removable relative to the pad stack, patterning a resist layer on the hard mask layer, the resist layer being selectively removable relative to the hard mask layer and having a thickness sufficient to prevent scalloping, etching the hard mask layer selective to the resist layer down to the pad stack, removing the resist layer. After removing the resist layer, the pad stack is etched selective to the hard mask layer such that a hole is opened down to the substrate.
Claims21
A method for opening holes in semiconductor fabrication comprising the steps of:
- providing a pad stack on a substrate;
- forming a hard mask layer on the pad stack;
- patterning a resist layer on the hard mask layer, the resist layer having a thickness to prevent scalloping;
- etching the hard mask layer selective to the resist layer down to the pad stack;
- removing the resist layer;
- and
- after removing the resist layer, etching the pad stack selective to the hard mask layer such that a hole is opened down to the substrate.
A method for forming deep trenches in semiconductor fabrication, comprising the steps of:
- providing a pad stack on a substrate;
- forming a hard mask layer on the pad stack, the hard mask layer having a thickness of greater than about 700 nm;
- patterning a resist layer on the hard mask layer, the resist layer having a thickness to prevent scalloping;
- etching the hard mask layer selective to the resist layer down to the pad stack layer;
- removing the resist layer;
- after removing the resist layer, etching the pad stack selective to the hard mask layer such that a hole is opened down to the substrate;
- and
- etching the substrate to form deep trenches using the hard mask layer as a mask such that the thickness of the hard mask layer enables the deep trenches to be formed to a depth of greater than or equal to 7 microns.
A method for opening holes for contacts in semiconductor fabrication comprising the steps of:
- providing a dielectric layer on a target layer;
- forming a hard mask layer on the dielectric layer;
- patterning a resist layer on the hard mask layer, the resist layer having a thickness to prevent scalloping;
- etching the hard mask layer selective to the resist layer down to the dielectric layer;
- removing the resist layer;
- after removing the resist layer, etching the dielectric layer selective to the hard mask layer such that a hole is opened down to the target layer;
- and
- depositing a conductive material in the hole such that a contact is formed to the target layer.
Dependencies are inferred from the claim text.