Holography and plasma oxidation for uniform nanoscale two dimensional channel formation of vertical organic field-effect transistors with suppressed gate leakage current

Vertical organic field-effect transistors (VOFETs) with nanoscale channel openings have been fabricated using pentacene as an active layer material. To achieve uniform nanoscale two-dimensional channel openings, a laser holography lithography has been introduced. Uniformly distributed and well-aligned holes with 250 nm diameter were successfully obtained with the laser holography lithography. VOFET devices with these channel openings have shown high on/off ratio of about 103 without any further treatment. Gate leakage current was also decreased with an additional insulating layer generated on the gate electrode sidewall via plasma oxidation.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We made pentacene-based vertical organic field-effect transistors (VOFETs). ► Laser holography lithography was introduced to make nanoscale channel openings. ► Uniformly distributed nanoscale two-dimensional channel openings were realized. ► Plasma oxidation was performed to oxidize sidewalls of gate electrodes in openings. ► Insulating sidewalls further reduced gate leakage current by MIS structure formation.