Several lithographic techniques are used for patterning in the nanoscale region. Electron beam lithography (EBL) is a highly accurate nanolithographic technique with extremely small resolutions available.
How Electron Beam Lithography (EBL) Works
In a similar manner to how a scanning electron microscope or CRT television works, EBL uses a computer controlled, tightly focussed electron beam to scan across a substrate material and selectively expose a sensitised resist coating. The resist can either be chemically developed in a method similar to photolithography, or the electron beam can be strong enough to sufficiently remove the resist material.
Figure 1. Basic illustration of how Electron Beam Lithography (EBL) works
Applications for EBL include:
• Cryo-electric devices
• Opto-electronic devices
• Optical devices
• Quantum structures
• Studies of semiconductor/superconductor interfaces
EBL can currently produce features as small as 20nm and is expected to be able to produce sub 1nm features with further development. The drawback to EBL is that it is very expensive and time consuming. For example a lithographic process that would take 5 minutes using photolithography would take approximately 5 hours using EBL.