Today’s high performance electron beam tools are very sensitive to changing ambient magnetic fields. The fields move the beam causing loss of resolution and measurement accuracy. Fields which exceed the tool manufacturer’s enviromental specification are common, created by nearby machinery and equipment as well as by external sources. Operation in such fields prevents the tools from reaching their full performance. The Spicer Consulting Field Cancelling systems stabilise the ambient magnetic field to restore the resolution and accuracy of the electron beam tool. Spicer Consulting’s field cancelling systems are recognised by equipment manufacturers and leading users as the simplest and most effective way to to resolve problems associated with magnetic interference, enabling greater flexibility in the siting of SEMs, TEMs and FIBs and allowing them to perform to their full potential. SC20 FAST The SC20 FAST is a new version of our established SC20 field cancelling system that has been optimised to cancel the high frequency fields, typically at 9 kHz, from robotic wafer transports in 300 mm wafer fabs. These fields limit the performance of electron beam tools in the fab and are a barrier to achieving the next semiconductor device CD node. Where there are also bad DC fields, an SC20/DCMR sensor can be added to the system. The outputs from the AC and DC sensors are combined with a 25Hz crossover frequency in a small adapter box that plugs into the back of the control unit. When the DC sensor is added, the cancelling factor is increased at low frequencies. The cancelling factor at 9kHz is unchanged. The SC20FAST also works with the remote monitor designed for the standard SC20 to remotely monitor the status and measure field levels.