Field effect organic transistor

• US 7,795,611 B2
• Filed: 07/02/2004
• Issued: 09/14/2010
• Est. Priority Date: 07/14/2003
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Nakamura, Shinichi
• Primary Examiner(s): Such; Matthew W
• Application Number:
  US10/555,303
• Publication Number:
  US 20070034860A1
• Time in Patent Office: 2,265 Days
• Field of Search: 438/99, 257/40, 257E51001-E51052
• US Class Current: 257/40
• CPC Class Codes: H10K 10/26 Diodes comprising organic-organic junctions
• CPC Class Codes: H10K 10/466 Lateral bottom-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/468 characterised by the gate dielectrics
• CPC Class Codes: H10K 10/486 the channel region comprising two or more active layers, e.g. forming pn heterojunctions
• CPC Class Codes: H10K 85/113 Heteroaromatic compounds comprising sulfur or selene, e.g. polythiophene
• CPC Class Codes: H10K 85/1135 Polyethylene dioxythiophene [PEDOT]; Derivatives thereof
• CPC Class Codes: H10K 85/311 Phthalocyanine
• CPC Class Codes: H10K 85/615 Polycyclic condensed aromatic hydrocarbons, e.g. anthracene

Abstract

A field effect organic transistor includes a source electrode, a drain electrode, a gate electrode, a gate insulating layer and an organic semiconductive layer; in the field effect organic transistor, the organic semiconductive layer includes a first organic semiconductive layer forming a channel region and a second organic semiconductive layer arranged to abut the first organic semiconductive layer; the charge mobility (μ₁) in the first organic semiconductive layer is 10⁻³ cm²/Vs or more; the charge mobility (μ₂) in the second organic semiconductive layer is 10⁻⁴ cm²/Vs or less; and the ratio (μ₁/&μ₂) between the two organic semiconductive layers is 10 or more.

Claims

1. A field effect organic transistor comprising a source electrode, a drain electrode, a gate electrode, a gate insulating layer and an organic semiconductive layer, the organic semiconductive layer comprising a first organic semiconductive layer and a second organic semiconductive layer, wherein

the source electrode and the drain electrode are arranged on the same surface of the gate insulating layer;

the first organic semiconductive layer and the second organic semiconductive layer are laminated in a channel region between the source electrode and the drain electrode;

the first organic semiconductive layer is arranged at a position nearer than the second organic semiconductive layer to the gate electrode;

the mobility in the first organic semiconductive layer is higher than the mobility in the second organic semiconductive layer;

the first organic semiconductive layer comprises pentacene;

the second organic semiconductive layer comprises copper phthalocyanine; and

the first organic semiconductive layer comes into contact with only side portions of the source electrode and the drain electrode;

a portion of the second organic semiconductive layer is arranged in the channel region; and

the second organic semiconductive layer comes into contact with a top surface of each of the source electrode and the drain electrode.

2. The field effect organic transistor according to claim 1, in which the ratio (μ

₁/μ

₂) between the mobility (μ

₁) in the first organic semiconductive layer and the mobility (μ

₂) in the second organic semiconductive layer is 10 or more.

3. The field effect organic transistor according to claim 1, wherein the gate insulating layer is constructed with an organic compound.

4. The field effect organic transistor according to claim 1, wherein the first organic semiconductive layer extends from a side surface of the source electrode to a side surface of the drain electrode.

5. The field effect organic transistor according to claim 1, wherein the portion of the second organic semiconductive layer arranged in the channel region is thicker than the first organic semiconductive layer.