AMORPHOUS OXIDE AND FIELD EFFECT TRANSISTOR

• US 20130277672A1
• Filed: 06/20/2013
• Published: 10/24/2013
• Est. Priority Date: 11/10/2004
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.), Japan Science & Technology Trading Co. Limited, Tokyo Institute of Technology (National University Corporation Tokyo Institute of Technology)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.), Tokyo Institute of Technology (National University Corporation Tokyo Institute of Technology)
• Inventors: SANO, MASAFUMI, NAKAGAWA, KATSUMI, HOSONO, HIDEO, KAMIYA, TOSHIO, NOMURA, KENJI
• Granted Patent: US 9,130,049 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02592 amorphous
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 21/428 using electromagnetic radiation, e.g. laser radiation
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 29/78693 the semiconducting oxide being amorphous
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

A novel amorphous oxide applicable, for example, to an active layer of a TFT is provided. The amorphous oxide comprises microcrystals.

Claims

1-21. -21. (canceled)

22. A field effect transistor comprising:

a gate electrode,

a gate insulator, and

an active layer of an amorphous oxide,

wherein the amorphous oxide has a composition varying in a layer thickness direction and has an electron carrier concentration of 10¹²/cm³ or more and less than 10¹⁸/cm³.

23. The field effect transistor according to claim 22, wherein the composition is set such that the concentration of oxygen near the gate insulator is greater than the concentration of oxygen in a region away from the gate insulator.

24. The field effect transistor according to claim 22, wherein the amorphous oxide is any one selected from the group consisting of an amorphous oxide containing In, Zn and Sn;

an amorphous oxide containing In and Zn;

an amorphous oxide containing In and Sn;

an amorphous oxide containing In; and

an amorphous oxide containing In, Ga and Zn.

25. The field effect transistor according to claim 24, wherein the composition is set such that the concentration of In near the gate insulator is greater than the concentration of In in a region away from the gate insulator.

26. The field effect transistor according to claim 24, wherein the composition is set such that the concentration of Zn near the gate insulator is greater than the concentration of Zn in a region away from the gate insulator.

27. A field effect transistor comprising:

a gate electrode,

a gate insulator, and

an active layer of an amorphous oxide,

wherein the amorphous oxide further contains one element or a plurality of elements selected from the group consisting of Li, Na, Mn, Ni, Pd, Cu, Cd, C, N, P, Ti, Zr, V, Ru, Ge, and F, and

wherein the amorphous oxide has an electron carrier concentration of 10¹²/cm³ or more and less than 10¹⁸/cm³.

28. The field effect transistor according to claim 27, wherein the amorphous oxide is any one selected from the group consisting of an amorphous oxide containing In, Zn and Sn;

an amorphous oxide containing In and Zn;

an amorphous oxide containing In and Sn;

an amorphous oxide containing In; and

an amorphous oxide containing In, Ga and Zn.