Multiple current exposure without mark detection

1
Multiple current exposurewithout mark detection

• Possible? Tolerance?
• Using only the 4th lens
• 1st exposure 0.1nA, 2nd aperture (min. current)
• 2nd exposure 10nA, 2nd aperture (max. current)

2
Multiple current exposurewith mark detection

• Requires a prior lithography (UV or ebeam)
• Using only the 4th lens
• small features, 0.1nA, 1st aperture
• large features, 10nA, 3rd aperture
• Using the 4th and 5th lens
• small features, 5th lens, 30pA, 1st aperture
• large features, 4th lens, 10nA, 3rd aperture

3
Switching between 5th and 4th lens

• There is a shift in coordinates between the
  lenses