The Process Improvement Study Of PNL-WCVD

With the increasing integration of integrated circuit, the transistorspeed faster and faster. Device critical dimensions continue to shrink,result in delays of interconnect delay than switch IC devices become mainfactors affect the speed of the entire device. In order to lower interconnectdelay, metal interconnects has undergone dramatic change. In the processof0.13um and beyong, copper process and low dielectric has widely used,greatly reduce the transmission delay, while also reducing the use oftungsten plug. But due to the diffusion of copper issue can be not solved,so the tungsten as the connection of the first layer of metal and the deviceis still used as a mainstream technology, and the performance of the wholeinterconnection system is particularly important.This thesis is focused on the study of pulsed nucleation chemicalvopour deposition (PNL-CVD) system and process for tungsten plug.Firstly, the PNL-WCVD process and chamber mechanism are introduced.Then the effect of various process parameters on the growth of tungstenthin film are analyzed. The process performance are discussed from theview of nucleation steps, bulk tungsten growth, electrical characteristics,and so on.The PNL-WCVD are optimized based on a series of experimentalanalysis. The resistivity of tungsten are reduced to10uΩ cm below fromoriginal14-15uΩ cm and can meet the requirement of advanced VLSImanufacturing...