Gang Liu

US Patent:

7948042, May 24, 2011

Filed:

Mar 3, 2009

Appl. No.:

12/397183

Inventors:

Chun Ning Lau - Diamond Bar CA, US
Gang Liu - Riverside CA, US
Jairo Velasco, Jr. - Riverside CA, US

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

H01L 29/84

US Classification:

257415, 257417, 257419, 257E43002, 257E43003, 257E43007, 257E27005, 257E27046, 257E27064

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.