Field-effect transistor comprising a layer of an organic semiconductor

A method of forming a field-effect transistor comprising the steps of:

• (i) depositing a pattern of metal or carbon on a substrate corresponding to the source and drain electrodes of the transistor,
• (ii) depositing a layer of functional organic semiconductor over the pattern,
• (iii) forming a via hole through the functional organic semiconductor to the source electrode,
• (iv) depositing a column of injection material in the via hole and which contacts the source electrode,
• (v) depositing an insulator layer on the functional organic semiconductor layer, and
• (vi) depositing a pattern of conductive material on the insulator layer corresponding to the gate electrode of the transistor,
• the injection material being arranged to facilitate the transfer of charge carriers between the source electrode and the channel.

A method of forming a field-effect transistor comprising the steps of:

• (i) depositing a pattern of conductive material on a substrate corresponding to the gate electrode of the transistor,
• (ii) depositing thereon an insulator layer,
• (iii) depositing thereon a layer of functional organic semiconductor,
• (iv) forming a via hole in the functional organic semiconductor,
• (v) depositing a column of injection material in the via hole, and
• (vi) depositing a pattern of metal or carbon on the functional organic semiconductor corresponding to the source and drain electrodes of the transistor, the source electrode being in contact with the column of the injection material,
• the injection material being arranged to facilitate the transfer of charge carriers between the source electrode and the channel.