Abstract: A multi-level lithography processes for the fabrication of suspended structures are presented. The process is based on the differential exposure and developing conditions of several a plurality of resist layers, without harsher processes, such as etching of sacrificial layers or the use of hardmasks. These manufacturing processes are readily suited for use with systems that are chemically and/or mechanically sensitive, such as graphene. Graphene p-n-p junctions with suspended top gates formed through these processes exhibit high mobility and control of local doping density and type. This fabrication technique may be further extended to fabricate other types of suspended structures, such as local current carrying wires for inducing local magnetic fields, a point contact for local injection of current, and moving parts in microelectromechanical devices.

Abstract: A multi-level lithography processes for the fabrication of suspended structures are presented. The process is based on the differential exposure and developing conditions of several a plurality of resist layers, without harsher processes, such as etching of sacrificial layers or the use of hardmasks. These manufacturing processes are readily suited for use with systems that are chemically and/or mechanically sensitive, such as graphene. Graphene p-n-p junctions with suspended top gates formed through these processes exhibit high mobility and control of local doping density and type. This fabrication technique may be further extended to fabricate other types of suspended structures, such as local current carrying wires for inducing local magnetic fields, a point contact for local injection of current, and moving parts in microelectromechanical devices.