Back to results
US 8,512,587 B2Granted
Highly selective doped oxide etchant
AssigneeMicron Technology, Inc.
InventorsNiraj Rana, Prashant Raghu, Kevin Torek
Life of this patent
Estimating the term…
Abstract
Etch solutions for selectively etching doped oxide materials in the presence of silicon nitride, titanium nitride, and silicon materials, and methods utilizing the etch solutions, for example, in construction of container capacitor constructions are provided. The etch solutions are formulated as a mixture of hydrofluoric acid and an organic acid having a dielectric constant less than water, optionally, with an inorganic acid, and a pH of 1 or less.
Claims36
A method of etching a doped oxide material on a substrate, comprising:
- selectively etching the doped oxide material relative to an exposed silicon nitride material on the substrate by applying an etch solution comprising a 5-20:1:>0-3 (v/v/v) mixture of and a monocarboxylic organic acid:hydrofluoric acid:inorganic acid, the organic acid having a dielectric constant of less than 3 and selected from the group consisting of butyric acid, isobutyric acid, valeric acid, caproic acid and caprylic acid.
A method of etching a doped oxide material on a substrate, comprising:
- applying an etch solution comprising a 5-20:1:>0-3 (v/v/v) mixture of monocarboxylic organic acid:hydrofluoric acid:inorganic acid to a substrate comprising the doped oxide material and an exposed low temperature, chlorinated, inorganic silicon nitride material to etch the doped oxide material relative to the low temperature silicon nitride material at a selectivity of about 250-400:1, the organic acid having a dielectric constant of less than 3 and selected from the group consisting of butyric acid, isobutyric acid, valeric acid, caproic acid and caprylic acid.
A method of etching a doped oxide material on a substrate, comprising:
- applying an etch solution comprising a 5-20:1:>0-3 (v/v/v) mixture of monocarboxylic organic acid:hydrofluoric acid:inorganic acid to a substrate comprising the doped oxide material and an exposed high temperature, chlorinated, inorganic silicon nitride material to etch the doped oxide material relative to the high temperature silicon nitride material at a selectivity of about 1000-1500:1, the organic acid having a dielectric constant of less than 3 and selected from the group consisting of butyric acid, isobutyric acid, valeric acid, caproic acid and caprylic acid.
A method of etching a doped oxide material on a substrate, comprising:
- applying an etch solution comprising an about 5-20:1:>0-3 (v/v/v) mixture of a monocarboxylic organic acid:hydrofluoric acid:inorganic acid to a substrate comprising the doped oxide material and an exposed silicon nitride material and polysilicon material to etch the doped oxide material selectively relative to the silicon nitride material and the polysilicon material at less than about 10 Å/minute, the organic acid having a dielectric constant of less than 3 and selected from the group consisting of butyric acid, isobutyric acid, valeric acid, caproic acid and caprylic acid.
A method of forming a plurality of capacitor devices, comprising:
- forming openings extending into a doped oxide layer and an overlying silicon nitride layer;
- forming a conductive container structure comprising a conductive material layer within the openings, the conductive container structure having an opening extending therein, an outer surface along the doped oxide layer, and a laterally opposed inner surface within the opening;
- removing a portion of the silicon nitride layer to expose the doped oxide layer adjacent a segment of the outer surface of the conductive container structures, while retaining portions of the silicon nitride layer connecting adjacently positioned conductive container structures;
- and
- removing a portion of the doped oxide layer selectively relative to the silicon nitride and the conductive material layer to expose the segment of the outer surface of the conductive container structures by applying an etch solution comprising an about 5:1 to 20:1 (v/v) mixture of a monocarboxylic organic acid:hydrofluoric acid and an inorganic acid up to a volume of greater than zero to about 3, the organic acid having a dielectric constant of less than 3 and selected from the group consisting of butyric acid, isobutyric acid, valeric acid, caproic acid and caprylic acid.
2 more elements
A method of forming a plurality of capacitor devices, comprising:
- forming openings extending into a doped oxide layer and an overlying silicon nitride layer;
- forming a conductive container structure comprising a conductive material layer within the openings, the conductive container structure having an opening extending therein, an outer surface along the doped oxide layer, and a laterally opposed inner surface within the opening;
- forming a layer of polysilicon over the silicon nitride layer and the conductive material layer within the openings;
- removing a portion of the polysilicon layer and the silicon nitride layer to expose the doped oxide layer adjacent a segment of the outer surface of the conductive container structures, while retaining portions of the silicon nitride layer connecting adjacently positioned conductive container structures;
- and
- removing a portion of the doped oxide layer selectively relative to the polysilicon layer, the silicon nitride layer, and the conductive material layer to expose the segment of the outer surface of the conductive container structures by applying an etch solution comprising an about 5-20:1:>0-3 (v/v/v) mixture of a monocarboxylic organic acid:hydrofluoric acid:inorganic acid, the organic acid having a dielectric constant of less than 3 and selected from the group consisting of butyric acid, isobutyric acid, valeric acid, caproic acid and caprylic acid.
3 more elements
A method of forming a plurality of capacitor devices, comprising:
- forming a layer of doped oxide extending over a memory cell array region, a peripheral region, and an intermediate region therebetween;
- forming a layer of silicon nitride over the doped oxide layer;
- forming openings extending into the doped oxide layer over the memory cell array region, and a trench extending into the doped oxide layer over the intermediate region;
- forming a conductive layer within the openings and the trench, the conductive layer within the openings forming a conductive container structure having an opening extending therein, an outer sidewall along the doped oxide layer, and laterally opposed inner sidewall within the opening;
- removing a portion of the silicon nitride layer to expose the doped oxide layer adjacent a segment of the outer surface of the conductive container structures, while retaining portions of the silicon nitride layer connecting adjacently positioned conductive container structures;
- and
- removing a portion of the doped oxide layer selectively relative to the silicon nitride and the conductive material layer to expose the segment of the outer surface of the conductive container structures by applying an etch solution comprising an about 5-20:1:>0-3 (v/v/v) mixture of a monocarboxylic organic acid:hydrofluoric acid:inorganic acid, the organic acid having a dielectric constant of less than 3 and selected from the group consisting of butyric acid, isobutyric acid, valeric acid, caproic acid and caprylic acid.
4 more elements
A method of forming a plurality of capacitor devices, comprising:
- applying an etch solution to a construction comprising a memory cell array region, a peripheral region, and an intermediate region therebetween, a doped oxide material overlying said regions, a plurality of electrically conductive container structures within the doped oxide material over the memory cell array region, the container structures comprising an opening extending therein, an outer sidewall along the doped oxide material, and laterally opposed inner sidewall within the opening, and a silicon nitride material overlying portions of the doped oxide material and interconnecting adjacently positioned conductive container structures, with other portions of the doped oxide material exposed adjacent a segment of the outer surface of the conductive container structures,
- wherein the etch solution etches the doped oxide material selectively relative to the silicon nitride material to expose the outer surface of the conductive container structures, the etch solution comprising an about 5-20:1:>0-3 (v/v/v) mixture of a monocarboxylic organic acid:hydrofluoric acid:inorganic acid, the organic acid having a dielectric constant of less than 3 and selected from the group consisting of butyric acid, isobutyric acid, valeric acid, caproic acid and caprylic acid.
Dependencies are inferred from the claim text.