RESIST OUTGASSING

Overview of resist testing tools for the NXE platform

Based on our experience with the first generation resist outgassing tool that has been fully operational for about 4 years with very good up time, we have developed and delivered a next generation resist outgassing tool for measuring the contamination of optics from resist outgassing by using 13.5 nm EUV photon exposure, or alternatively by using e-beam exposure, of resist coated 300 mm wafers and witness samples.

Measurements are performed in an ultra-clean measuring chamber equipped with a high sensitive residual gas analyzer (RGA), so as not to add background (non-resist related) contamination, a separate electron gun illuminates the witness sample for cracking hydrocarbons during exposure and supplied with a LabView based extremely user-friendly and reliable control system.

This system can also be supplied initially with the e-beam exposure option and field upgrading to a photon exposure system by the addition of an Energetiq EQ-10 EUV source

Salient features of the basic system the Model No. RER300-EX

  • Kimball Physics EFG-7F/EGPS-2017 electron gun (wafer e-gun) capable of producing e-beam energies of 2000 eV to 5000 eV to expose resist-coated wafers, positioned to illuminate the resist-coated wafer at 90 degrees to the wafer surface and to illuminate approximately 10 mm diameter spot on the wafer.
  • A separate Kimball Physics EFG-7F/ EGPS-1017 electron gun capable of producing an e-beam energies of 50 eV to 2000 eV to illuminate the witness sample at 90 degrees to its surface for cracking hydrocarbons during exposure to contamination with a spot size of 2 to 4 mm.
  • All metal, low hydrocarbon, UHV measurement chamber that will accommodate a 200 mm or a 300 mm wafer and a lubricant free, in-vacuum R-theta scanning stage to translate the wafer and rotate it through 360 degrees to expose its entire surface.
  • High sensitive UHV RGA detection system, 1-200 amu, minimum detectable partial pressure of 5 10-13 mbar and fast data acquisition rates to check the cleanliness of the measurement chamber and to quantify resist out-gassing products.
  • Load lock equipped with a semi-automatic UHV Brooks vacuum robotic transfer system to transfer the 200mm or 300mm wafer to the main chamber and to unload it.
  • Semi-automatic vacuum transfer system to transfer the witness sample to the main chamber and to unload it.
  • User-friendly LabView based software to control the tool, for data analysis and to integrate dose snake analysis with an ellipsometer (not included).
  • Ability to perform dose exposure to determine the dose-to-clear for the resist used.
  • A calibrated leak valve and integrated heaters for baking the chamber.
  • Additional features of Model No. RER300-PEX

  • A novel optical system to provide in-band spectrum of illumination of the resist-coated wafers by integrating the Energetiq EQ-10
  • A filter shield to extend the lifetime of zirconium filters when photon excitation is used.
  • Ability to perform true dose snakes using EUV radiation to determine the dose-to-clear for the resist used.
  • Continuous monitoring of the source output EUV power using a high accuracy EUV detector when photon excitation is used.