一种采用苯并环丁烯介质隔离的片上变压器工艺  

A Process for On-Chip Transformers with Benzocyclobutene Dielectric Isolation

作　　者：周国[1] 罗和平[2] 廖龙忠[1] 陈卓 张力江[1] Zhou Guo;Luo Heping;Liao Longzhong;Chen Zhuo;Zhang Lijiang(The 13^(th)Research Institute,CETC,Shijiazhuang 050051,China;School of Electronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu 610054,China)

机构地区：[1]中国电子科技集团公司第十三研究所,石家庄050051 [2]电子科技大学电子科学与工程学院,成都610054

出　　处：《半导体技术》2022年第7期539-543,共5页Semiconductor Technology

摘　　要：片上变压器是实现磁耦数字隔离器设计的核心元件,需要采用特殊的工艺流片技术,以实现数字隔离器芯片的小型化和3000 V以上的高压隔离能力。为了实现片上变压器的制备,开发了一种利用光敏型苯并环丁烯(BCB)介质隔离的工艺流程。该工艺可实现均匀的介质层厚度和良好的附着能力。通过对合金成分的种子层进行刻蚀实现片上变压器线圈线条的图形化,再采用电镀实现片上变压器线圈的制备。测试结果表明:变压器芯片的金属线圈厚度约为3μm,BCB隔离介质层厚度大于10μm,介质层平坦化效果良好,与金属线圈及硅表面附着紧密,变压器最高工作频率接近600 MHz。On-chip transformer is the key element to realize the design of magnetic-couple digital isolator.Special process techniques are required to achieve the miniaturization of digital isolator chip and the high-voltage isolation capacity above 3000 V.A process flow using photosensitive benzocyclobutene(BCB)dielectric isolation was developed to achieve the fabrication of on-chip transformers,which can achieve uniform dielectric layer thickness and good adhesion.The seed layer with alloy composition was etched to realize the patterning of the on-chip transformer coil lines,and then the on-chip transformer coils were prepared by electroplating.The test results show that the thickness of the metal coil of the transformer chip is about 3μm,and the thickness of BCB dielectric isolation layer is greater than 10μm.The flattening effect of the dielectric layer is good,and it is closely attached to the metal coil and the silicon surface.The maximum operating frequency of the transformer is nearly 600 MHz.

关 键 词：片上变压器 苯并环丁烯(BCB) 数字隔离器 电流隔离 电镀 

分 类 号：TN305.95[电子电信—物理电子学]