Thin film fabrication of Bi-2(Sr,Ca)(2)CuOx phase at temperatures between 450 and 650 degrees C by plasma-assisted ion beam sputtering

Thin films of Bi-2(Sr, Ca)(2)CuOx (2201) were prepared by ion beam sputtering with supply of oxygen molecules or plasma to the substrate at various substrate temperatures T-s. The high-quality 2201 single phase can be grown with T-s in the range of 550-600 degrees C using oxygen molecules, while it can be grown in the range of 450-650 degrees C using oxygen plasma. Use of this plasma allows reduction of the processing temperature by 100 degrees C and suppresses 2201 dissociation at higher T-s. X-ray linewidths of the films prepared using plasma are extremely narrow, like those of MBE-grown films fabricated at higher T-s using ozone or atomic oxygen, indicating that the films have thick crystalline domains and less strain.