Organic inverter including surface-treated layer and method of manufacturing the same

An inverter, comprising:

• a p-type load transistor including a gate electrode, source and drain electrodes, a load insulating layer formed on the gate electrode, the source electrode being connected to the gate electrode, and an organic semiconductor layer formed on the load insulating layer;
• a p-type driver transistor connected to the p-type load transistor and including a gate electrode, source and drain electrodes, a driver insulating layer formed on the gate electrode, and an organic semiconductor layer formed on the load insulating layer, wherein the drain electrode of the p-type driver transistor is directly connected to the gate electrode of the p-type load transistor;
• and
• a surface-treated layer formed on a predetermined insulating layer, the predetermined insulating layer being one of the load insulating layer and the driver insulating layer, such that the load transistor is a depletion-type transistor and the driver transistor is an enhancement-type transistor,
• wherein the p-type load transistor and the p-type driver transistor have substantially the same W/L ratio.