Method for processing a niobium type thin film and method for manufacturing a superconducting integrated circuit

摘要

The present invention provides a processing method for suppressing variation in the characteristics of a Josephson junction using a niobium type thin film. In the processing method of the present invention, CF4 gas to which CHF3 gas has been added is used as the etching gas in reactive ion etching. As a result, the etching rate is lowered so that high-precision etching control is facilitated. In addition, it is desirable that magnesium oxide is used as mask of this etching, because etching amount of the mask become reduced. In the superconducting integrated circuit manufacturing method of the present invention, the processing method of the present invention is used to process the counter-electrode of a Josephson junction. As a result, variation in the junction area can be reduced; accordingly, variation in the characteristics of the Josephson junction can be reduced.