A current source with metrological precision made in a 300mm silicon MOS process

Although the measurement of current is now defined with respect to the electronic charge, producing a current standard based on a single-electron source remains challenging. The error rate of a source must be below 0.01 ppm, and many such sources must be operated in parallel to provide practically useful values of current in the nanoampere range. Achieving a single electron source using an industrial grade 300 mm wafer silicon metal oxide semiconductor (MOS) process could offer a powerful route for scaling, combined with the ability for integration with control and measurement electronics. Here we present measurements of such a single-electron source indicating an error rate of 0.008 ppm, below the error threshold to satisfy the SI Ampere, and one of the lowest error rates reported, implemented using a quantum dot device fabricated on an industry-grade silicon MOS process. Further evidence supporting the accuracy of the device is obtained by comparing the device performance to established models of quantum tunnelling, which reveal the mechanism of operation of our source at the single particle level. The low error rate observed in this device motivates the development of scaled arrays of sources utilising Si MOS devices to realise a new generation of metrologically accurate current standards.