|LCD pattern formation agents|
We produce and sell chromium film etching solution for use in the manufacturing process of color filter (CF) for LCD and photomask. In addition, it can be used for the replenishment of the Etchant for Cr/Concentration control system (Anac Corporation).
|Production items||CAN(%)||Perchloric acid(%)||Nitric acid(%)|
|Etchant for Cr Nitric acid-system items(※)||11～22||―||3～10|
|Etchant for Cr Perchloric acid-system items(※)||11～22||2～10||―|
(※)CAN (Cerium Ammoniumu Nitrate)
Appropriate for fine pattern etching;
When Ce4+ ions coexist in chromium etching reaction at a concentration greater than a certain value, a stable etching rate is achieved owing to the reaction below. Conversely, if the concentration of Ce4+ is smaller than 0.24 M , etching solution should be renewed, because the etching rate becomes extremely low.
If the concentration of (NH4)2Ce(NO3)6 is lower than 12% in both nitric acid- and perchloric acid-system etching solution, the etching rate shows a tendency to decrease extremely as the fatigue is increased. Perchloric acid-system etching solution apparently changes into a composition close to that of nitric acid etching-system solution. The reason why cerium- system etching solution is made strong acid by adding nitric acid is to inhibit sludge produced by the hydrolysis of (NH4)2Ce(NO3)6 and to stabilize the oxidation-reduction potential.