Authors: K.E. Burcham, J. Fridmann, J. Klingfus, J.E. Sanabia
Affilation: Raith USA, United States
Pages: 261 - 264
Keywords: EBIE, electron beam, FEBIP
We present our work using FEBIP processes to etch nanopores within a silicon nitride membrane. We utilize an electron beam rastered in concentric rings rather than a position fixed beam to reduce charging of the membrane and the effects of gas depletion in the etched region. This method provides greater control of the hole dimensions and reduces the amount of peripheral etching that causes the hole dimensions to enlarge. Charging and the associated beam position drift are critical for this process and can’t be completely eliminated by adjusting the process physical parameters, such as beam energy. Therefore, a periodic correction to the beam position is necessary, either by referencing the developing structure itself or by referencing separate marks. We discuss ways of further refinement and automation of this process and the challenges for bringing the process to the wafer level.