Study On The Material Removal Mechanism Of Wafer Using Water-based Polishing Slurry By Experiment

Chemical mechanical polishing technology is the only surface finishing technology which can provide global planarization.It has been recognized as the best method and has been widely used in integrate circuit manufacturing. To accurately control the CMP process, the material removal mechanism muse be understood.The mechanism involves in material,tribology,chemistry and other disciplines.In view of the key scientific issues faced by chip processing and the development trend of chip both at home and abroad,green ultra-precision machining technology has become the focus of research.This issue uses green slurry-DI water and hydrogen peroxide to study the mechanical action influence on chemical reaction in CMP process.In this issue, the materrial removal mechanism of single crystal silicon CMP has been studied from the friction and wear behavior.The main research work and results are listed as follows:1. According to the friction and wear theory and non-continuous material removal mechanism(atomic/molecular mechanism). Through the friction and wear experiments, the friction and wear properties of single crystal silicon under dry frication, water lubrication,H₂O₂ lubrication and static state of H₂O₂ corrosion have studied,the conclusions are the following: The wear mechanism under dry frication and static state of H₂O₂ corrosion is regarded to be of adhesive wear.Molecule-scale removal process is dominant under water lubrication.The wear mechanism under H₂O₂ lubrication is mainly spalling caused by micro-cracks.2. The friction and wear properties of single crystal silicon under the four conditions are analysed.It indicates that under water lubrication and H₂O₂ lubrication, the mechanical action can promote chemical reaction,which leads to the formation of Si(OH)4 film possessing lubrication performance. Furthermore, the sliding depth is on the order of 0.1 nm and the wear rate are small,so it is possible to realize green chemical mechanical polishing without damage.