Sub Monolayer Silicon Oxide Growth Rate versus Oxygen Concentration in UPW

摘要

The growth rate of ultra-thin sub-monolayer "native oxide" on a HF cleaned silicon (100) surface during a ultra-pure water (UPW) rinse was studied at room temperature. The study was accomplished by stripping the oxide layer and analyzing it for Si using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). It was demonstrated that the rapid acid etching method developed in our laboratory coupled with ICP-OES is capable of detecting and clearly distinguishing the difference in native oxide growth within a monolayer range with a possible 0.2 A resolution. The initial results obtained indicate that the native oxide growth is significantly affected by both the exposure tune of a silicon surface to UPW and the dissolved oxygen concentration in UPW. The significance of control of the dissolved oxygen concentration in UPW for advanced ULSI processes was demonstrated in a post-UPW rinse polycrystalline silicon deposition process.