Aluminum Layer Etching

Aluminum is commonly used as a conductive layer material in semiconductor manufacturing. Wet etching of aluminum layers can be performed using the following inorganic acids and bases:

1. HCl

2. NaOH or KOH

3. H₃PO₄ / HNO₃

4. H₃PO₄ / HNO₃ / CH₃COOH

Among these, the mixed solution in item (4) provides the most stable etching effect and is widely used in semiconductor processes today. The main process principle involves the chemical reaction between HNO₃ and the aluminum layer, followed by the dissolution and removal of Al₂O₃ by H₃PO₄:

2Al + 6HNO₃ → Al₂O₃ + 3H₂O + 6NO₂
Al₂O₃ + 2H₃PO₄ → 2AlPO₄ + 3H₂O

The typical etch rate is controlled at approximately 3000 Å/min.

Packaging type：200L drum