Field effect transistor using oxide film for channel and method of manufacturing the same

• US 8,003,981 B2
• Filed: 08/03/2007
• Issued: 08/23/2011
• Est. Priority Date: 03/17/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kumomi, Hideya, Iwasaki, Tatsuya
• Primary Examiner(s): Fahmy; Wael M
• Assistant Examiner(s): Salerno; Sarah K
• Application Number:
  US12/282,000
• Publication Number:
  US 20090065771A1
• Time in Patent Office: 1,481 Days
• Field of Search: 257/43, 257/E29.296
• US Class Current: 257/43
• 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 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• CPC Class Codes: H01L 29/78621 with LDD structure or an extension or an offset region or characterised by the doping profile
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

The present invention provides a field effect transistor including an oxide film as a semiconductor layer, wherein the oxide film includes one of a source part and a drain part to which one of hydrogen and deuterium is added.

Claims

1. A field effect transistor, comprising an amorphous oxide film as a semiconductor layer,

wherein the amorphous oxide film includes a channel part, a source part, and a drain part, and

wherein a hydrogen concentration of at least one of the source part and the drain part is equal to or larger than 10¹⁷/cm³, and a concentration of one of hydrogen and deuterium in the source part and the drain part is larger than a concentration of one of hydrogen and deuterium in the channel part.

2. A field effect transistor according to claim 1, wherein the source part and the drain part are disposed in self-alignment with a gate electrode, and have a coplanar structure.

3. A field effect transistor according to claim 1, wherein a resistivity of at least one of the source part and the drain part is 1/10 or less of a resistivity of the channel part.

4. A field effect transistor according to claim 1, wherein the oxide film is formed of an amorphous oxide represented by:

[(Sn_1-xM4_x)O₂]a.[(In_1-yM3_y)₂O₃]b.[(Zn_1-zM2_zO)]c,

where 0≦

x≦

1;

0≦

y≦

1;

0≦

z≦

1;

0≦

a≦

1, 0≦

b≦

1, 0≦

c≦

1, and a+b+c=1;

M4 is a group VI element selected from a group that includes Si, Ge, and Zr smaller in atomic number than Sn;

M3 is Lu or a group III element selected from a group that includes B, Al, Ga, and Y smaller in atomic number than In; and

M2 is a group II element selected from a group that includes Mg and Ca smaller in atomic number than Zn.

5. A field effect transistor according to claim 1, wherein

the field effect transistor is incorporated in a display device with a display element that includes an electrode, and

one of a source part and a drain part of the field effect transistor is electrically connected with the electrode of the display device.

6. A field effect transistor according to claim 5,

wherein the display element is one of a plurality of display elements, and the field effect transistor is one of a plurality of field effect transistors, and

wherein the plurality of display elements and the plurality of field effect transistors are two-dimensionally arranged on a substrate.

7. A field effect transistor according to claim 1, wherein a hydrogen concentration of at least one of the source part and the drain part is equal to or larger than 10¹⁹/cm³.

8. A field effect transistor comprising:

an amorphous oxide semiconductor layer including a channel region;

a gate electrode;

a gate insulator;

a drain electrode; and

a source electrode,

wherein the amorphous oxide semiconductor layer further includes a pair of doped regions adjacent to the source electrode or the drain electrode, each of the doped regions including at least one of hydrogen and deuterium, and

wherein a hydrogen concentration of at least one of the source electrode and the drain electrode is equal to or larger than 10¹⁷/cm³ and a concentration of one of hydrogen and deuterium in the doped regions is larger than a concentration of one of hydrogen and deuterium in the channel region.

9. A field effect transistor according to claim 8, wherein a resistivity of at least one of the source electrode and the drain electrode is equal to or smaller than 1/10 of a resistivity of the channel region.

10. A field effect transistor according to claim 8, wherein a hydrogen concentration of at least one of the source electrode and the drain electrode is equal to or larger than 10¹⁹/cm³.