摘要
为了降低集成电路中的互连延迟,采取了一种新型的集成电路Cu互连工艺,以掩膜电镀的方法制备Cu互连的叠层结构,借鉴MEMS工艺的牺牲层技术,用浓磷酸对Al2O3牺牲层进行湿法刻蚀,不仅在互连金属间介质层而且在层内介质层都形成了以空气为介质的Cu互连悬空结构。用一种叉指测试结构对以空气和聚酰亚胺为介质的互连性能进行了比较,结果表明,采用空气介质减小了互连线耦合电容,为进一步降低集成电路的互连延迟提供了途径。
A novel air-gap copper interconnects process was studied. Freestanding copper beams were prepared after removing Al2O3 sacrificial layer by wet-etching. In this copper freestanding structure, intralevel dielectric （ILD） and inter-metal dielectric （IMD） were both air-dielectric. A fork test structure was used to evaluate the air-dielectric in comparison with polyimide-dielectric interconnects. The results show that the coupling capacitance of air-dielectric interconnects is shrank greatly. In conclusion, this new process provides an opportunity for reduction of the delay due to conductor lines.
出处
《半导体技术》
CAS
CSCD
北大核心
2007年第9期768-770,775,共4页
Semiconductor Technology
基金
上海市纳米专项(0552nm043)
上海市AM基金(0511)
关键词
CU互连
空气气隙
牺牲层材料
低介电常数
电容
copper interconnects
air gap
sacrificial layer material
low dielectric constant
capacitance
