用于200 V电平位移电路的薄层SOI高压LDMOS

摘要

High voltage thin layer SOI devices based on 1.5-μm-thick silicon layer have been designed for 200 V level shift circuit. The designed devices include thin gate oxide nLDMOS and thick gate oxide pLDMOS. Multiple field plates are induced in both nLDMOS and pLDMOS for achieving high breakdown voltage. Field implant technology is adopted in pLDMOS to avoid punch-through breakdown induced by back gate effect. The influences of drift length and implantation dose,as well as field plates on breakdown voltage are discussed. Experiment results show that the breakdown voltage of nLDMOS and pLDMOS are 344 V and 340 V, respectively. A 200 V level shift circuit using the designed devices has been successfully realized.%　　文章基于1.5μm厚顶层硅SOI材料，设计了用于200 V电平位移电路的高压LDMOS，包括薄栅氧nLDMOS和厚栅氧pLDMOS。薄栅氧nLDMOS和厚栅氧pLDMOS都采用多阶场板以提高器件耐压，厚栅氧pLDMOS采用场注技术形成源端补充注入，避免了器件发生背栅穿通。文中分析了漂移区长度、注入剂量和场板对器件耐压的影响。实验表明，薄栅氧nLDMOS和厚栅氧pLDMOS耐压分别达到344 V和340 V。采用文中设计的高压器件，成功研制出200 V高压电平位移电路。