The Torr-Seal gluing method was often used to attach the nanofabricated leak elements to the vacuum system. However, such new leaks are difficult to be applied in ultrahigh vacuum due to the strong outgassing effect of Torr-Seal. To eliminate such issue and achieve enclosed sealing of leak element and CF flange, a new nanofluidic channels type leak assembly has been fabricated based on the glass frit sealing method. Nanofluidic channels with a feature dimension of ∼162 nm were enclosed as a leak element using reactive ion etching and silicon direct bonding processes. The outgassing rate of the leak assembly was analyzed by a residual gas analyzer. The results exhibit that the outgassing rate with the glass paste is 1 order of magnitude lower than that with the Torr-Seal. The flow conductance of helium, nitrogen, and argon was characterized by the difference method. It is found that the measured values are close to the calculated values and the molecular flow is achieved from vacuum to atmosphere pressure.

Atmosphere pressure; Calculated values; Difference method; Feature dimensions; Glass-frit sealing; Nanofluidic channel; Residual gas analyzers; Silicon direct bondings

HeFei University of Technology; University of Science and Technology of China