Fabricating nanoscale and atomic scale devices

A method for fabricating a nanoscale or atomic scale device, comprising the steps of:

• creating one or more registration markers visible to a Scanning Tunnelling Microscope (STM), Scanning Electron Microscope (SEM) or an optical microscope, on or in a (clean) silicon surface;
• using a SEM or optical microscope to form an image of at least one of the registration markers and the tip of a Scanning tunnelling Microscope (STM) in the vicinity of the registration marker;
• using the image to position and reposition the STM tip relative to the marker with nanometer or micron resolution in order to pattern the active region of the device structure on the silicon surface;
• the device and then encapsulating it with silicon such that one or more of the registration markers are still visible on the silicon surface to a SEM or optical microscope;
• depositing a metal layer onto the silicon surface using either optical or electron beam lithography to form one or more ohmic or gate electrodes, or both, at one or more locations positioned relative to respective registration markers.