One disadvantage of HSQ and Medusa 82 is the comparably low sensitivity, which can however be increased by an addition of photoacid generators.

Sensitivity increase by a factor of 20 after addition of PAG (30 kV)

  • Resist: SX AR-N 8200.06/1 – 100 nm
  • Coating: 60 s 4000 rpm
  • Soft-bake: 15 min @ 120°C
  • Exposure: 30 kV
  • Development: 90 s AR 300-44; 23 °C
  • Stopping: 30 s DI-water

Sensitivity increase by a factor of 5 after addition of PAG (100 kV)

  • Resist: SX AR-N 8200.06/1 – 100 nm
  • Coating: 60 s 4000 rpm
  • Soft-bake: 10 min @ 130 °C
  • Exposure: 100 kV
  • Development: 90 s AR 300-44; 23 °C
  • Stopping: 30 s DI-water

In the case of e-beam exposure at 30 kV, the sensitivity could be increased by a factor of 20, and at 100 kV by about a factor of 5. The sensitivity can be adjusted by varying the PAG content in the resist.

Sensitivity increase by a factor of 5 after addition of PAG (100 kV)

Interestingly, the sensitivity of the standard resist Medusa 82 (without PAG addition) can also be increased by a PEB (for example 5 min at 180 °C; see diagram, black line). The resist patterns obtained differ only slightly as compared to patterns with addition of PAGs (see Medusa: Influence of post exposure bake).