Etching reagent, and method for manufacturing electronic device substrate and electronic device
View Patent ↗The present invention provides an etching agent that is able to etch a Cu film by a simple chemical etching method such as an immersion method when the low resistance Cu film is used for a wiring material, while allowing time-dependent changes of the etching rate to be small and preventing a pattern narrowing phenomenon ascribed to irregular amount of side etching of the Cu film from occurring, by providing an etching agent comprising an aqueous solution containing potassium hydrogen peroxosulfate and hydrofluoric acid, wherein masks of a give pattern is formed on the surface of a laminated film prepared by sequentially depositing a Ti or Ti alloy film and a Cu film on a substrate, and wherein a gate electrode (a laminated wiring) and a lower pad layer (a laminated wiring) with give patterns are formed by etching the laminated film using the etching agent having the foregoing construction.
1. An aqueous anisotropic copper etching agent consisting of potassium hydrogen peroxomonosulfate having a concentration within a range of about 0.08 to about 2.0 mol/l, and acetic acid, said etching agent etching the copper at an approximately uniform rate throughout the etching process, wherein the acetic acid functions as a wetting agent, and wherein the acetic acid is within a range of about 10 wt. % to about 75 wt. % relative to the potassium hydrogen peroxomonosulfate.
2. An etching agent according to claim 1 , wherein
said etching agent selectively etches copper.
3. An anisotropic copper etching agent for anisotropically etching a copper layer having an overlying mask pattern in an etching process, the etching agent consisting of an aqueous solution including potassium hydrogen peroxomonosulfate having a concentration within a range of about 0.08 to about 2.0 mol/l and acetic acid within a range of about 10 wt. % to about 75 wt. % relative to the potassium hydrogen peroxomonosulfate, said etching agent etching the copper layer at an approximately uniform rate throughout the etching process, such that edges of the copper layer are substantially continuous with corresponding edges of the mask pattern.
4. An etching agent according to claim 3 , wherein said etching agent selectively etches the copper layer.
5. An aqueous anisotropic copper etching solution, wherein the etching solution is formulated to anisotropically etch a copper layer having a mask pattern thereon, the solution consisting of potassium hydrogen peroxomonosulfate and acetic acid, wherein the acetic acid continuously wets exposed surfaces of the copper layer and the potassium hydrogen peroxomonosulfate uniformly etches the copper layer, such that the copper layer is etched to substantially the same dimensions as the mask pattern, and wherein the acetic acid is within a range of about 10 wt. % to about 75 wt. % relative to the potassium hydrogen peroxomonosulfate.
6. The aqueous anisotropic copper etching solution of claim 5 , wherein the solution comprises a potassium hydrogen peroxomonosulfate concentration of about 0.08 to about 2.0 mol/l.
7. The aqueous anisotropic copper etching solution of claim 6 , wherein the solution comprises a weight ratio of acetic acid to potassium hydrogen peroxomonosulfate of about 10% to about 75%.
8. The aqueous anisotropic copper etching solution of claim 5 , wherein the copper layer has a thickness of about 100 nm to about 200 nm.
9. The aqueous anisotropic copper etching solution of claim 5 , wherein the solution etches the copper layer such that edges of the copper layer are substantially continuous with corresponding edges of the mask pattern.
10. The aqueous anisotropic copper etching solution of claim 5 , wherein the copper layer is layer comprises a gate electrode.
11. The aqueous anisotropic copper etching solution of claim 5 , wherein the copper layer comprises a wiring layer.
12. An aqueous etching agent consisting of potassium hydrogen peroxomonosulfate having a concentration within a range of about 0.08 to about 2.0 mol/l, and acetic acid, wherein the acetic acid is within a range of about 10 wt. % to about 75 wt. % relative to the potassium hydrogen peroxomonosulfate.