Blanker assembly employing dielectric material

摘要

A blanker assembly for an electron beam column obtains synchronicity between the beam blanking signal propagating through its blanker plates and the associated electron beam which is being blanked. Since the blanking signal travels faster than does the electron beam, the desired synchronicity is achieved by use of a dielectric material for propagating the blanking signal to slow down this signal to match the electron beam velocity. By using a dielectric material for high frequency (RF) blanking signals, there will be less signal reflection and greater blanking accuracy because the electron beam is continuously deflected. The blanker plates each include a substance having a relatively low dielectric constant for proipagating the blanking signal between an upper deflection region. The relative slowness of the propagation of the blanking signal between the upper and lower deflection regions provides a delay effect so as to synchronize the blanking signal with the associated electron beam.