The Research About Using DIO₃ Instead Of SPM For LDD PR Striping Process In 40nm And Beyond Technical Node

As sub-40 nm technology has been going to be more dominant and moving into mass production,several challenges and requirements have arisen for the traditional integrated circuit manufacturing process.Wet Cleaning has been an essential part within the integrated circuit manufacture.Traditional bench cleaning process has been gradually replaced by single-wafer cleaning process as the continuing decrease of particle size along with the higher requirement for cleaning uniformity,but on the other hand,the reformation also brings higher process cost and increasing environment contamination problems.In this paper,we researched a DIO₃ process,which can replace the traditional SPM process,has been used in FEOL Light Doped Drain?LLD?process at the 40nm technology node for polymer stripping.The object of this promising process application is to reduce process cost,environmental pollution and safety hazard,and meanwhile not to affect the device or circuit yield.Based on the current application status,this paper makes a comparison between SPM and DIO₃ polymer removal process,analyses pros and cons of traditional SPM process,presents advantages and also application challenges?mainly for silicon depletion control?of DIO₃process.And by comparative analysis of SPM and DIO₃ polymer stripping principle,the subsequent theoretical researches showed the feasibility of this study.Batch experiments determine final process conditions to solve silicon depletion and other problems,from a series of experimental comparison of TEM test,defect scanning and WAT electrical test.And also discuss the different etch loss result between blanket wafer and full loop wafer.This paper concluded that DIO₃ process can be used in 40nm LDD polymer stripping process instead of SPM.This process also can be used in28nm LDD polymer stripping process.It has been confirmed by TEM test and defect scanning test.