Method of anisotropic extraction of silicon nitride mandrel for fabrication of self-aligned block structures
First Claim
1. A method of preparing a self-aligned block (SAB) structure, comprising:
- providing a substrate having raised features defined by a first material containing silicon nitride and a second material containing silicon oxide formed on first and second side walls of the first material in which the first and second side walls are spaced from each other in a lateral direction such that the first material is between the second material on the first and second side walls, and a third material spaced laterally from the first and second side walls of the first material and containing an organic material covering some of the raised features and exposing some raised features according to a block pattern formed in the third material;
forming a first chemical mixture by plasma-excitation of a first process gas containing H and optionally a noble gas;
exposing the first, second, and third materials on the substrate to the first chemical mixture such that after exposing to the first chemical mixture a depth within the first material is hydrogenated;
thereafter, forming a second chemical mixture by plasma-excitation of a second process gas containing S, F, and optionally a noble element; and
exposing the first, second, and third materials on the substrate to the second plasma-excited process gas to selectively etch the first material relative to the second and third materials and to remove the first material while the second and third materials remain after exposing to the second plasma-excited process gas.
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Accused Products
Abstract
A method of preparing a self-aligned block (SAB) structure is described. The method includes providing a substrate having raised features defined by a first material containing silicon nitride and a second material containing silicon oxide formed on side walls of the first material, and a third material containing an organic material covering some of the raised features and exposing some raised features according to a block pattern formed in the third material. The method further includes forming a first chemical mixture by plasma-excitation of a first process gas containing H and optionally a noble gas, and exposing the first material on the substrate to the first chemical mixture. Thereafter, the method includes forming a second chemical mixture by plasma-excitation of a second process gas containing N, F, O, and optionally a noble element, and exposing the first material on the substrate to the second plasma-excited process gas to selectively etch the first material relative to the second and third material.
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Citations
19 Claims
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1. A method of preparing a self-aligned block (SAB) structure, comprising:
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providing a substrate having raised features defined by a first material containing silicon nitride and a second material containing silicon oxide formed on first and second side walls of the first material in which the first and second side walls are spaced from each other in a lateral direction such that the first material is between the second material on the first and second side walls, and a third material spaced laterally from the first and second side walls of the first material and containing an organic material covering some of the raised features and exposing some raised features according to a block pattern formed in the third material; forming a first chemical mixture by plasma-excitation of a first process gas containing H and optionally a noble gas; exposing the first, second, and third materials on the substrate to the first chemical mixture such that after exposing to the first chemical mixture a depth within the first material is hydrogenated; thereafter, forming a second chemical mixture by plasma-excitation of a second process gas containing S, F, and optionally a noble element; and exposing the first, second, and third materials on the substrate to the second plasma-excited process gas to selectively etch the first material relative to the second and third materials and to remove the first material while the second and third materials remain after exposing to the second plasma-excited process gas. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method of preparing a self-aligned block (SAB) structure, comprising:
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providing a substrate having raised features defined by a first material containing silicon nitride and a second material containing silicon oxide formed on first and second side walls of the first material in which the first and second side walls are spaced from each other in a lateral direction such that the first material is between the second material on the first and second side walls, and a third material spaced laterally from the first and second side walls of the first material and containing an organic material covering some of the raised features and exposing some raised features according to a block pattern formed in the third material; forming a first chemical mixture by plasma-excitation of a first process gas containing H and optionally a noble gas; exposing the first, second, and third materials on the substrate to the first chemical mixture such that after exposing to the first chemical mixture a depth within the first material is hydrogenated; thereafter, forming a second chemical mixture by plasma-excitation of a second process gas containing a high fluorine content molecule, and optionally a noble element, wherein the ratio of fluorine to other atomic elements of the high fluorine content molecule exceeds unity; and exposing the first, second, and third materials on the substrate to the second plasma-excited process gas to selectively etch the first material relative to the second and third materials and to remove the first material while the second and third materials remain after exposing to the second plasma-excited process gas. - View Dependent Claims (19)
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Specification