PURPOSE: To form thin film coil with excellent precision by a method wherein more than one or two thin film layers are laminated on a metallic thin film to be successively etched into specified coil shape.
CONSTITUTION: An Al thin film 50 around 3μm thick is laminated on an insulating film 2 on a magnetic substrate 1 by means of sputter evaporation etc. and SiO2 film 8 is laminated on the film 50. Then a mask 9 is formed by photoresist and etched by CF4, H2 mixed gas to form the SiO2 film into specified coil shape. Next the Al thin film 50 is etched using the SiO2 film 80 preliminarily formed into coil shape with Cl2, BCl3 mixed gas as a mask. A thin film 5a thus formed is covered with another insulating film 6a and after forming an opening 6c on a contact 5c with a thin film coil to be formed on the insulating film 6a, the SiO2 film 80 is removed by means of etching process using CF4, H2 mixed gas.
KIYOOKA SHIGERU
OKITA HIROAKI
TAKEI SHIYUUJI
