Patent ID: 8860008
Filing Date: 2014-10-14
Classification: H01L,Y02E

Abstract:
1. An electronically functional device comprising: a substrate; a gate electrode on the substrate; a gate dielectric material formed over the gate electrode; a first electrode region and a second electrode region formed on the gate dielectric material; and an active channel region formed between the first electrode region and the second electrode region as a result of a drop-cast printing technique that applies at least one droplet of a first liquid onto the first electrode region, then applies at least one droplet of a second liquid containing dissolved organic semiconductor materials onto the first liquid such that the second liquid accumulates at a base of the first liquid due to hydrophobic-hydrophilic interactions between the first and second liquids, and organic crystals for the active channel region are formed upon evaporation of at least the second liquid, whereby the organic crystals formed as a result of crystallization after the drop-cast printing technique have a particular molecular orientation in a highest mobility direction, have relatively minimal grain boundaries and have relatively low trap densities, wherein the organic crystals are at least partially disposed on the first electrode region and radially around an annular central portion of the first electrode region that is not covered by the organic crystals; wherein the first electrode region is a drain electrode on the substrate, the second electrode region is a source electrode around a periphery of the drain electrode, and the gate electrode is located beneath the gate dielectric material and under the drain electrode and the source electrode, wherein the drain electrode, the source electrode, and the gate electrode form an organic field-effect transistor (OFET) and the active channel region is formed between the drain electrode and the source electrode, wherein an amount of the first and second liquids used in the drop-cast printing technique and conditions for drop-cast procedures depend upon particular characteristics of the active channel region to be formed, and wherein the conditions for drop-cast procedures are related to at least one of droplet amount, liquid viscosity, liquid evaporation rates, drop height, drop angle, drop atmosphere, and drop splash, and the characteristics of the active channel region are related to at least one of depth, width, height, configuration, and other physical dimensions thereof.