Landing pad technology doubled up as local interconnect and borderless contact for deep sub-half micrometer IC application

摘要

The present invention is directed to a technology that simplifies the process of fabricating multilayer interconnects and reduces capacitance in integrated circuits employing multilayer interconnects. The novel landing pad technology of the present invention simplifies the current process steps involved in the formation of multilayer interconnects. The same contact/via etch, the same PVD TiN deposition, etc., can be modularized and repeated to build up multilayer metalization. The process of the present invention for forming multilayer interconnects involves the formation of Ti/TiN stack interconnect structures that can be used as local interconnects and contact landing pads on the same level. The contact landing pads facilitate the use of a borderless contact approach which enables a reduction in the size of the source-drain area. As the source-drain area is reduced, junction capacitance decreases, and packing density can be increased. Source-drain real estate can be also be minimized by using the Ti/TiN stack interconnect structures as contact landing pads in the implementation of raised source-drain technology. The Ti/TiN stack interconnect structures can also be used as short local interconnects in SRAM devices.