Dose Assignments for Exposures on Thin Membranes

Motivation:

Thin membranes are widely used in the fabrication of biosensors and microelectromechanical systems. However, when preparing patterns for exposure on substrates such as silicon nitride membranes, the significant difference in electron scattering on-membrane and off-membrane can prevent the use of standard BEAMER proximity effect correction (PEC) or topography-PEC (topo-PEC).

Solution:

By simulating the electron scattering on and off-membrane using TRACER, we can estimate the contrast in base dose between the two regions. In BEAMER, each area of the pattern is proximity effect corrected separately and the difference in required dose is accounted for using the Feature Dose Assignment (FDA) module.