200MHz高传输效率薄膜变压器的设计与制备

Design and Preparation High Efficiency Thin-Film Transformer at 200MHz

实现了一种新型的基于硅IC工艺的微波铁氧体集成薄膜变压器．铁氧体薄膜采用射频磁控溅射法制备，SEM观察了SiO2层上铁氧体膜的表面形貌，表明薄膜容易开裂；能谱仪对薄膜成分的分析表明铁氧体薄膜与SiO2层和Al膜附着性差．通过溅射工艺参数及增加热处理等工艺初步解决了以上存在的薄膜制备工艺与IC工艺之间的兼容性问题．采用标准硅基IC工艺设计和制备了这种新型结构的薄膜变压器，对一组薄膜变压器样品的实验参数在20～210MHz的频率范围内作了测试．测试结果表明：对于设计的匝数比为1的薄膜变压器，在90～210MHz的频率范围内能获得最高为79％的变压比和良好的波形传输能力．

A novel microwave ferrite thin-film transformer based on Si IC technology was presented. RF magnetron sputtering was used to prepare ferrite thin film on SiO2 layer. The ferrite film of surface appears crack by observation of SEM. EDS analysis of thin film showed that thin film has poor cohesiveness to SiO2 layer or Al film. These compatible problems of thin film with IC technology were resolved through sputtering parameters modification and heating treatment addition. The thin-film transformer was fabricated and transmission parameters have been measured at 20 MHz～210 MHz. Experience results showed that the maximal Vout and Vin radio of the thin-film transformers is approximately 79% at 90 MHz～210 MHz, and the thin-film transformer has fine waveform transmission ability at 20 MHz to 210 MHz.