Organic field-effect transistor and production thereof

• US 5,854,139 A
• Filed: 09/10/1997
• Issued: 12/29/1998
• Est. Priority Date: 06/28/1994
• Status: Expired due to Term

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi, Ltd.
• Inventors: Aratani, Sukekazu, Kondo, Katsumi, Ohara, Shuichi
• Primary Examiner(s): Chaudhari, Chandra
• Assistant Examiner(s): Berry, Renee R.
• Application Number:
  US08/926,498
• Time in Patent Office: 475 Days
• Field of Search: 257/40, 438/780, 438/782
• US Class Current: 438/780
• CPC Class Codes: H10K 10/46 Field-effect transistors, e.g. organic thin-film transistors [OTFT] H10K10/43 takes precedence
• CPC Class Codes: H10K 10/464 Lateral top-gate IGFETs comprising only a single gate
• 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 85/111 comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
• CPC Class Codes: H10K 85/113 Heteroaromatic compounds comprising sulfur or selene, e.g. polythiophene
• CPC Class Codes: H10K 85/114 Poly-phenylenevinylene; Derivatives thereof

Abstract

A field-effect transistor using a conjugated oligomer having an ionization potential of 4.8 eV or above in the semiconductor layer thereof works stably and has a long life-time and can be used in a liquid crystal display device as a switching element to give excellent contrast and good performances.

Claims

1. A process for producing a field-effect transistor comprising a step of preparing a solution of a conjugated oligomer having an ionization potential of 4.8 eV or above and a step of forming a semiconductor layer by a dipping method.

2. A process for producing a field-effect transistor comprising a step of preparing a solution of a conjugated oligomer having an ionization potential of 4.8 eV or above and a step of forming a semiconductor layer by a printing method.

3. A process for producing a field-effect transistor comprising a step of preparing a solution of a conjugated oligomer having an ionization potential of 4.8 eV or above and a step of forming a semiconductor layer by a spin-coating method.

4. A process for producing a field-effect transistor comprising:

(A) a step of forming a gate electrode on an insulating substrate,

(B) a step of forming an insulating film on said gate electrode,

(C) a step of forming a semiconductor layer constituted of a conjugated oligomer having an ionization potential of 4.8 eV or above by the use of a solution of said conjugated oligomer, and

(D) a step of forming a source electrode and a drain electrode on said semiconductor layer.

5. A process for producing a field-effect transistor comprising:

(A) a step of forming a source electrode and a drain electrode on an insulating substrate,

(B) a step of forming a semiconductor layer constituted of a conjugated oligomer having an ionization potential of 4.8 eV or above on said source electrode and drain electrode by the use of a solution of said conjugated oligomer,

(C) a step of forming an insulating film on said semiconductor layer, and

(D) a step of forming a gate electrode on said insulating film.

6. A process for producing a field-effect transistor comprising

(A) a step of forming a gate electrode on an insulating substrate,

(B) a step of forming an insulating film on said gate electrode,

(C) a step of forming a source electrode and a drain electrode on said insulating film, and

(D) a step of forming a semiconductor layer constituted of a conjugated oligomer having an ionization potential of 4.8 eV or above on said source electrode and drain electrode by the use of a solution of said conjugated oligomer.

7. A process for producing a field-effect transistor comprising a step of patterning a semiconductor layer constituted of a conjugated oligomer having an ionization potential of 4.8 eV or above by laser ablation method.

8. A process for producing a field-effect transistor comprising patterning a semiconductor layer constituted of a conjugated oligomer having an ionization potential of 4.8 eV or above through a partial conversion of the semiconductor layer to an insulating material by the method of ultraviolet irradiation.