Chrome on glass mask writing at 75 kV with the IBM EL4+electron-beam system

The IBM EL4+mask writer, located in the Advanced Mask Facility in Burlington, Vermont has recently been used to investigate chrome on glass lithography at 75 kV with a current density of 60 A/cm2. One of the main concerns with doing lithography at high beam voltages on a quartz substrate is the effect of beam heating on the resist. Using ZEP7000 resist on both quartz glass and silicon wafer substrates, we have characterized image size control from 0.1 to 3 μm for a large range of pattern geometries.