Reduction of Particle Contamination in Plasma-Etching Equipment by Dehydration of Chamber Wall

Abstract

The mechanism of particle generation is investigated in order to prevent defects formed on wafers in the plasma etching of multi-layered films composed of tungsten silicide (WSi) and polycrystalline silicon (poly-Si). Particles are measured by an in situ monitoring system using laser light scattering during the etching process. The particles are composed of AlF 3 , which is presumably generated by reacting the coating material Al 2 O 3 on the etching chamber wall with plasma containing fluorine atoms, F in the presence of H 2 O absorbed into the chamber parts and materials. We demonstrated successfully that dehydration of the chamber parts and materials by plasma discharge suppresses particle generation.

Fabrication of dense yttrium oxyfluoride ceramics by hot pressing and their mechanical, thermal, and electrical properties

“…The size of particle contaminants from multilayered films consisting of tungsten silicide (WSi) and polycrystalline silicon (poly-Si) has been reported to be around 0.05-0.1 µm. 18) The particles contaminate the IC surface. The short current in the circuits and the lower production yield are caused by particle contamination.…”

Comparison of Erosion Behavior and Particle Contamination in Mass-Production CF4/O2 Plasma Chambers Using Y2O3 and YF3 Protective Coatings

“…These materials interact with plasma and are eroded, resulting in the production of contaminant particles on the wafer. As integrated circuits continue to scale down with wider use of high-density plasma for wafer processing, the particles generated in the plasma processing equipment cause serious problems, such as short current in integration circuit and lower production yield [6,7]. In order to solve this problem, yttrium oxide (Y 2 O 3 ) was adopted as plasma-facing inner wall materials in plasma processing equipment because their plasma erosion resistance values are much higher than those of conventional SiO 2 coatings [8,9,10].…”

Hydrogenation Effects on Chemical Activity of Defects in Excimer-Laser-Annealed Polycrystalline Silicon Thin Films

“…The plasmasurface interaction induces the changes in the sticking and recombination probabilities of radicals on the wall, 1) resulting in the changes in gas-phase radical densities and surface reactions. Although it is speculated that the changes in gasphase radical densities and surface reactions induce process drifts 2,3) and/or particle generation, [4][5][6] the detailed mechanism and its influence on the process performance have not been understood yet. Al 2 O 3 is a popular plasma-facing material used for the inner walls of plasma processing tools.…”

“…It is pointed out in mass production that Al 2 O 3 inner walls have problems of significant erosion and particle generation when they are exposed to fluorine-based plasmas. [4][5][6] We have reported the difference in fluorination between Al 2 O 3 and Y 2 O 3 surfaces when they are irradiated by high-density CF 4 /O 2 and SF 6 /O 2 plasmas, and have discussed the fluorination mechanisms. 7) The objective of this work is to investigate the effects of the irradiations of H 2 and O 2 plasmas onto a fluorinated Al 2 O 3 surface.…”