Etchant for etching metal wiring layers and method for forming thin film transistor by using the same
View Patent ↗The present invention discloses an etchant for etching at least two different metal layers, the etchant comprising hydrogen peroxide (H 2 O 2 ) and one of carboxylic acid, carboxylate salt, and acetyl group (CH 3 CO—). The present invention also discloses a method of fabricating a metal wiring on a substrate, the method comprising forming a first metal layer on a substrate, forming a second metal layer on the first metal layer, and simultaneously etching the first metal layer and the second metal layer with an etchant comprising hydrogen peroxide (H 2 O 2 ) and one of carboxylic acid, carboxylate salt, and acetyl group (CH 3 CO—).
1. An etchant simultaneously etching at least two different metal layers, comprises hydrogen peroxide (H 2 O 2 ), fluorine (F) and one of carboxylate salt of sodium acetate (CH 3 COONa), and acetyl group (CH 3 CO—),
wherein the fluorine (F) has a concentration of about 0.1 wt % or more,
wherein the carboxylate salt of sodium acetate has a concentration of about 0.5 wt % or more, and the hydrogen peroxide (H 2 O 2 ) has a concentration of about 0.1 mol or more, and
wherein the acetyl group (CH 3 CO—) includes one of ammonium pivalate ((CH 3 ) 3 C 2 OONH 4 ), sodium pivalate ((CH 3 ) 3 C 2 OONa), and potassium pivalate ((CH 3 ) 3 C 2 OOK).
2. An etchant simultaneously etching at least two different metal layers including at least copper/titanium (Cu/Ti), comprising hydrogen peroxide (H 2 O 2 ), fluorine (F) and one of carboxylate salt and acetyl group (CH 3 CO—),
wherein the fluorine (F) has a concentration of about 0.1 wt % or more,
wherein the carboxylate salt has a concentration of about 0.5 wt % or more, and the hydrogen peroxide (H 2 O 2 ) has a concentration of about 0.1 mol or more,
wherein the carboxylate salt includes sodium acetate (CH 3 COONa), and
wherein the acetyl group (CH 3 CO—) includes one of ammonium pivalate ((CH 3 ) 3 C 2 OONH 4 ), sodium pivalate ((CH 3 ) 3 C 2 OONa), and potassium pivalate ((CH 3 ) 3 C 2 OOK).