Fabrication of 30nm T-Gate High Electron Mobility Transistors Using a Bi-Layer of PMMA and UVIII

This work reports on the development and fabrication of high electron mobility transistors with a gate length of less than 30 nm. The T-shaped gates were realized using a two-stage "bi-lithography" process that creates a T-shaped image in a bi-layer of PMMA and UVIII. This is then transferred into SiO
₂
gate support layer by a low damage dry-etch process. This method enables the fabrication of mechanically robust, ultra short T-gates to be realised