Novel method to achieve increased trench depth, independent of CD as defined by lithography
AssigneeInternational Business Machines Corporation
InventorsKevin K. Chan, Subhash B. Kulkarni, Gangadhara S. Mathad, Rajiv M. Ranade
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Abstract
A method of forming at least one deep trench structure having an increased trench depth is provided. The method includes providing at least one deep trench having sidewalls that extend to a common bottom wall in a surface of a substrate. Each deep trench has initial dimensions that are wider than targeted dimensions for the deep trenches. To reduce the initial dimensions to that of the targeted dimensions, an epitaxial silicon film is formed selectively or non-selectively on at least some portions of the sidewalls using a low-temperature ultra-high vacuum epitaxial silicon growth tehnique.
Claims20
A method of forming at least one deep trench structure, said method comprising the steps of:
- providing at least one deep trench having sidewalls that extend to a common bottom wall in a surface of a substrate, each of said at least one deep trenches having initial dimensions that are wider than targeted dimensions for said deep trenches;
- and
- forming an epitaxial silicon film on at least some portions of said sidewalls so as to reduce the initial dimensions of said deep trenches to the targeted dimensions.
A method of forming at least one deep trench structure, said method comprising the steps of:
- providing at least one deep trench having sidewalls that extend to a common bottom wall in a surface of a substrate, each of said at least one deep trenches having initial dimensions that are wider than targeted dimensions for said deep trenches, said substrate having an upper surface which includes at least a pad material present thereon;
- forming an epitaxial silicon film on at least some portions of said sidewalls so as to reduce the initial dimensions of said deep trenches to the targeted dimensions;
- and
- forming a silicon dioxide film on said epitaxial silicon film.
A method of forming at least one deep trench structure, said method comprising the steps of:
- providing at least one deep trench having sidewalls that extend to a common bottom wall in a surface of a substrate, each of said at least one deep trenches having initial dimensions that are wider than targeted dimensions for said deep trenches;
- forming a liner on said sidewalls and said bottom wall of each deep trench;
- providing a recessed resist in a bottom portion of each deep trench;
- removing said liner from an upper portion of each deep trench so as to expose said upper portion of each deep trench;
- and
- forming an epitaxial silicon film on said upper portion of each deep trench so as to reduce the initial dimensions of said deep trenches to the targeted dimensions.
Dependencies are inferred from the claim text.