Thursday, September 26, 2019
Electron Beam Lithography Lab Report Example | Topics and Well Written Essays - 500 words
Electron Beam Lithography - Lab Report Example The linewidth has a directly proportional linear relation with the dosage provided. Lower dosage results in a decrease of linewidth; though at very low quantities, line discontinuity dominates. The relation that defines Line Dose is- Therefore, a change in line dose (which in turn affects linewidth) can be brought about by altering the beam current, dwell time or line step-size (with the last one being inversely proportional to linewidth values). The thickness of Polymethylmethacrylate (PMMA), which is often used as a resist in EBL, also has a linearly proportional relation with linewidth (Deng et al 2005). A reduction in PMMA thickness thins down the linewidth, and this can be done by either diluting the PMMA using Chlorobenzene, or using A series PMMA (in Anisole). Pattern resolution is primarily limited by either aberrations, or space charge. Furthermore, the feature resolution limit is determined by the forward scattering (effective beam broadening) in the resist, and the pitch resolution limit is determined by the secondary electron travel in the resist (Broers et al 1996). Reducing the beam spot size results in a decrease of the linewidth. The beam spot size is determined by two factors - the beam current (I), and the numerical aperture () - and hence, linewidth is also affected when a change is brought about in any of these factors.