CF4/Cl2/Ar 유도 결합 플라즈마에 의한 gold 박막의 식각특성

Abstract

The etching of Au thin films have been performed in an inductively coupled CF4/Cl2/Ar plasma. The etch rates were measured as CF4 contents added from 0 to 30 % to Cl2/Ar plasma, of which gas mixing ratio was fixed at 20%. Other parameters were fixed at an rf power of 700 W, a dc bias voltage of 150 V, a chamber pressure of 15 mTorr, and a substrate temperature of 30℃. The highest etch rate of the Au thin film was 3700 Åm/min at a 10 % additive CF4 into Cl2/Ar plasma. The surface reaction of the etched Au thin films was investigated using x-ray photoelectron spectroscopy (XPS) analysis. XPS analysis indicated that Au reacted with Cl and formed Au-Cl, which is hard to remove on the surface because of its high melting point. The etching products could be sputtered by Ar ion bombardment.