Back to results
US 6,783,694 B1Granted
Composition for selectively etching against cobalt silicide
AssigneeMicron Technology, Inc.
InventorsWhonchee Lee, Yongjun Jeff Hu
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeMicron Technology, Inc.
InventorsWhonchee Lee, Yongjun Jeff Hu
Estimating the term…
An etching method for use in integrated circuit fabrication includes providing a metal nitride layer on a substrate assembly, providing regions of cobalt silicide on first portions of the metal nitride layer, and providing regions of cobalt on second portions of the metal nitride layer. The regions of cobalt and the second portions of the metal nitride layer are removed with at least one solution including a mineral acid and a peroxide. The mineral acid may be selected from the group including HCl, H2SO4, H3PO4, HNO3, and dilute HF (preferably the mineral acid is HCl) and the peroxide may be hydrogen peroxide. Further, the removal of the regions of cobalt and the second portions of the metal nitride layer may include a one step process or a two step process. In the one step process, the regions of cobalt and the second portions of the metal nitride layer are removed with a single solution including the mineral acid and the peroxide. In the two step process, the regions of cobalt are removed with a first solution containing a mineral acid and a peroxide and the second portions of the metal nitride layer are removed with a second solution containing a peroxide. An etching composition including a mineral acid and a peroxide, preferably, HCl and hydrogen peroxide, is also described. The etching methods and compositions may be used in forming structures such as word lines, gate electrodes, local interconnects, etc.
An etching composition, the composition comprising a mineral acid, a peroxide, and deionized water at a ratio in a range of about 1:1:25 (mineral acid:peroxide:deionized water) to about 1:1:15 (mineral acid:peroxide:deionized water), wherein the composition has an etch rate greater than about 1000 Å/minute for cobalt at a temperature in a range of about 20 degrees centigrade to about 100 degrees centigrade and an etch rate of about 50 Å/minute to about 250 Å/minute for metal nitride at a temperature in a range of about 20 degrees centigrade to about 100 degrees centigrade.
An etching composition, the composition comprising a mineral acid, a peroxide, and deionized water at a ratio in a range of about 1:1:35 (mineral acid:peroxide:deionized water) to about 1:1:15 (mineral acid:peroxide:deionized water), wherein the composition has an etch rate greater than about 1000 Å/minute for cobalt at a temperature in a range of about 20 degrees centigrade to about 100 degrees centigrade.
An etching composition, the composition comprising a mineral acid, a peroxide, and deionized water at a ratio in a range of about 1:1:35 (mineral acid:peroxide:deionized water) to about 1:1:15 (mineral acid:peroxide:deionized water), wherein the composition has an etch rate of about 50 Å/minute to about 250 Å/minute for metal nitride at a temperature in a range of about 20 degrees centigrade to about 100 degrees centigrade.
An etching composition, the composition consisting essentially of a mineral acid, a peroxide, and deionized water at a ratio in a range of about 1:1:35 (mineral acid:peroxide:deionized water) to about 1:1:15 (mineral acid:peroxide:deionized water), wherein the composition has an etch rate of about 50 Å/minute to about 250 Å/minute for metal nitride at a temperature in a range of about 20 degrees centigrade to about 100 degrees centigrade and an etch rate greater than about 1000 Å/minute for cobalt at a temperature in a range of about 20 degrees centigrade to about 100 degrees centigrade.
An etching composition, the composition comprising a mineral acid, a peroxide, and deionized water at a ratio in a range of about 1:1:25 (mineral acid:peroxide:deionized water) to about 1:1:15 (mineral acid:peroxide:deionized water), wherein the mineral acid is selected from the group consisting of HCl diluted to 37% by weight in deionized water, HNO3 diluted to 70% by weight in deionized water, H2SO4 diluted to 96% by weight in deionized water, H3PO4 diluted to 85% by weight in deionized water, and HF diluted to 49% by weight in deionized water, wherein the peroxide is selected from the group consisting of hydrogen peroxide diluted to 29% by weight in deionized water, and ozone, and further wherein the composition has an etch rate greater than about 1000 Å/minute for cobalt at a temperature in a range of about 20 degrees centigrade to about 100 degrees centigrade.
An etching composition, the composition comprising a mineral acid, a peroxide, and deionized water at a ratio in a range of about 1:1:25 (mineral acid:peroxide:deionized water) to about 1:1:15 (mineral acid:peroxide:deionized water), wherein the mineral acid is selected from the group consisting of HCl diluted to 37% by weight in deionized water, HNO3 diluted to 70% by weight in deionized water, H2SO4 diluted to 96% by weight in deionized water, H3PO4 diluted to 85% by weight in deionized water, and HF diluted to 49% by weight in deionized water, wherein the peroxide is selected from the group consisting of hydrogen peroxide diluted to 29% by weight in deionized water, and ozone, and further wherein the composition has an etch rate of about 50 Å/minute to about 250 Å/minute for metal nitride at a temperature in a range of about 20 degrees centigrade to about 100 degrees centigrade.
Dependencies are inferred from the claim text.