Application of gold plated edges for the measurement of the electron beam diameter

Gold plated edges fabricated on bulk and thin substrates are used as targets in electron beam diameter measurements and for system calibration in a Cambridge Instruments E-Beam Lithography machine. A target of 0.85 μm thick gold plated on a 2 μm thick silicon nitride membrane is shown to significantly enhance the signal to noise ratio and also improves the reliability of diameter measurements for low beam currents at all beam energies. Typically a statistical accuracy of 5 nm (1 sigma value) for a beam diameter of 38 nm is achieved. Monte Carlo simulation has also been used to quantify the electron scattering effects which take place in the target.