FIELD EFFECT TRANSISTOR, ORGANIC THIN-FILM TRANSISTOR AND MANUFACTURING METHOD OF ORGANIC TRANSISTOR

• US 20080012009A1
• Filed: 03/14/2007
• Published: 01/17/2008
• Est. Priority Date: 07/13/2006
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Fujimori, Masaaki, Arai, Tadashi, Hashizume, Tomihiro, Suwa, Yuji
• Application Number:
  US11/685,958
• Publication Number:
  US 20080012009A1
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 10/466 Lateral bottom-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/84 Ohmic electrodes, e.g. source or drain electrodes
• CPC Class Codes: H10K 71/60 Forming conductive regions or layers, e.g. electrodes

Abstract

A method for determining the combination of the electrode and organic semiconductor with improved electron injection efficiency and hole injection efficiency in an organic TFT is provided, two types of FETS, that is, an n channel FET and a p channel FET are realized, and further, a complementary TFT (CTFT) is provided. The method for obtaining the vacuum level shift at the electrode metal/organic semiconductor interface from physical constants of constituent elements of the electrode and the organic semiconductor is provided. By changing the electrode metal through an electrochemical method, the electrodes whose electron injection and hole injection can be controlled are formed. By using these electrodes, two types of FETs such as an n channel FET and a p channel FET are realized, thereby providing a complementary TFT (CTFT).

Claims

1. A field effect transistor, comprising:

a plurality of source electrodes;

at least one drain electrode; and

an organic semiconductor thin film,

wherein at least one of the electrodes has oxidation characteristics or reduction characteristics.

2. The field effect transistor according to claim 1,

wherein a complementary transistor is formed using the plurality of source electrode and the drain electrode.

3. An organic thin-film transistor,

wherein a source electrode and a drain electrode are made of first metal, and surfaces of the electrodes are covered with a thin film with a thickness of 0.3 to 5 atomic layer made of compound of a second element and the first metal.

4. The organic thin-film transistor according to claim 3, comprising:

first and second source electrodes;

at least one drain electrode; and

an organic semiconductor thin film,

wherein one of the first source electrodes is made of any one of gold, silver, copper and titanium, and

the second source electrode is made of any one of gold, silver, copper, and titanium, and a surface of the second electrode is covered with a thin film with a thickness of 0.3 to 5 atomic layer made of sulfur, oxygen, halogen element, calcium or magnesium or compound of these elements and the electrode element.

5. The organic thin-film transistor according to claim 3, comprising:

first and second source electrodes;

at least one drain electrode; and

an organic semiconductor thin film,

wherein the first source electrode is made of gold, silver, copper or titanium,

the second source electrode is made of gold, silver, copper or titanium, and

a thin film with a thickness of 0.3 to 1 molecular layer containing pentafluorobenzenethiol, perfluoroalkylthiol, trifluoromethanethiol, pentafluoroethanethiol, heptafluoropropanethiol, nonafluorobutanethiol, sodium butanethiol, sodium butanoate thiol, or sodium butanol thiol is adsorbed to an surface of the second electrode.

6. A manufacturing method of an organic transistor, comprising the steps of:

forming first and second source electrodes, at least one drain electrode, and an organic semiconductor thin film; and

oxidizing or reducing at least one of the electrodes by electrochemical reaction in a solution or vapor phase reaction.

7. The manufacturing method of an organic transistor according to claim 6, further comprising the step of:

performing an adsorption process or a desorption process on a surface of at least one of the electrodes.

8. The manufacturing method of an organic transistor according to claim 6,

wherein, by successively passing a substrate on which the electrodes are formed through a solution or vapor phase, a surface of at least one of the electrodes is processed.