A preparative technique for spiral thin-film transformer at GHz frequency band

摘要

This paper present a preparative technique for spiral thin-film transformer with ferrite magnetic core. RF magnetron sputtering is used to prepare ferrite thin film on SiO2 layer. Compatible problems of thin film with IC technology are observed by SEM. The problems are resolved through sputtering parameters modification and heating treatment addition. S-parameters are measured at 10 MHz-20 GHz. The result shows that The experience result shows, magnetic core thin-film transformer with 15:15 ratio-turn can obtain the maximal transmission efficiency 80.9% at 10 MHz-20 GHz, and the air core transformer can obtain the maximal transmission efficiency 55.4% at same frequency range. Ferrite thin film can improve the transmission efficiency evidently.