【摘要】 采用气相沉积聚合法制备了聚酰亚胺(PI)薄膜及PI与金属颗粒(Cr)复合(PI/Cr)薄膜,所制备PI薄膜表面平整,随着金属颗粒体积百分数增加,PI/Cr薄膜介电常数逐渐增大;当将PI薄膜应用于压电微机械超声换能器(pMUTs)中时,pMUTs机电耦合系数显著提高,所研制pMUTs在光声成像演示中探测到了较强的光声信号;当将PI/Cr薄膜应用于AlGaN/GaN高电子迁移率场效应晶体管(HEMTs)中时,HEMTs的击穿电压由156 V提高到248 V,HEMTs器件的耐压能力显著改善。更多还原

【Abstract】 The polyimide(PI) thin films with smooth surface and polyimide/chromium(PI/Cr) composite thin films with high permittivity were prepared by vapor deposition polymerization(VDP).The piezoelectric micro-machined ultrasonic transducers(pMUTs) were fabricated by covering the PI thin films as acoustic impedance matching layer.And the AlGaN/GaN high-electron-mobility transistors(HEMTs) were fabricated by using high permittivity PI/Cr composite thin film as passivation layer.The electromechanical coupling coefficient of pMUTs is improved by introducing the PI layers,and the prepared pMUTs show good performance for photo-acoustic imaging.The breakdown voltage of the HEMTs increases from 156 V to 248 V by using the PI/Cr thin film dielectric field plate while maintaining high performance.更多还原