Effects of Wet Chemistry Pre-gate Clean Strategies on the Organic Contamination of Gate Oxides for Metal-Oxide-Semiconductor Field Effect Transistor

概要

論文の詳細を見る
It is known that organic contamination can seriously degrade the electrical performance of gate oxides for metal-oxide-semiconductor field effect transistor(MOSFET)applications. In this paper, organic contamination of wafer surfaces cleaned by different pre-gate clean conditions and subsequently exposed to cleanroom ambience was investigated using time-of-flight secondary ion mass spectroscopy(TOF-SIMS), and the carbon level from thermally decomposed organic species directly trapped in the gate oxides after thermal oxidation and polysilicon deposition was probed using secondary ion mass spectroscopy(SIMS)depth profiling. The C concentration in the oxide-polysilicon gate stack obtained from SIMS depth profiling closely correlates with the total TOF-SIMS peak intensity of organic contaminants detected on post clean wafer surfaces. A quantified carbon concentration on the order of 10^<12> atoms/cm^2 was obtained at the interfaces using SIMS depth profiling calibrated with an implanted C standard. It was found that the susceptibility of wafer surfaces to organic contamination that eventually affects the level of oxide-polysilicon interfacial carbon appears to be highly dependent on the surface termination.
2000-07-15