ETCHING METHOD AND DEVICE THEREFOR

PROBLEM TO BE SOLVED: To etch an aluminum into a shape having low taper angle by using as an etching gas a mixing gas consisting of a gas including at least a chlorine and a gas including an oxygen element. SOLUTION: After an etching gas is excited, an aluminum thin film is etched by at least a reactive ion generated through the excitation. In such a case, a mixing gas consisting of a gas including at least a chlorine and a gas including an oxygen element is used as an etching gas. For example, a helicon wave plasma device using low-pressure high-density plasma is used as an etching device, and a mixing gas BCl3 /O2 consisting of a gas including BCl3 and a gas including O2 is introduced as an etching gas from a first gas introduction tube 18. Then a high-density plasma is generated in a cylindrical quartz belljar 10, and an Al of a sample 20 is etched by reactive ions generated through excitation of the mixing gas BCl3 O2 and neutral active species.