FIELD EFFECT TRANSISTOR USING AMORPHOUS OXIDE FILM AS CHANNEL LAYER, MANUFACTURING METHOD OF FIELD EFFECT TRANSISTOR USING AMORPHOUS OXIDE FILM AS CHANNEL LAYER, AND MANUFACTURING METHOD OF AMORPHOUS OXIDE FILM

• US 20090045397A1
• Filed: 09/05/2006
• Published: 02/19/2009
• Est. Priority Date: 09/06/2005
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Iwasaki, Tatsuya
• Granted Patent: US 7,791,074 B2
• Time in Patent Office: Days
• 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 29/78693 the semiconducting oxide being amorphous

Abstract

An amorphous oxide containing hydrogen (or deuterium) is applied to a channel layer of a transistor. Accordingly, a thin film transistor having superior TFT properties can be realized, the superior TFT properties including a small hysteresis, normally OFF operation, a high ON/OFF ratio, a high saturated current, and the like. Furthermore, as a method for manufacturing a channel layer made of an amorphous oxide, film formation is performed in an atmosphere containing a hydrogen gas and an oxygen gas, so that the carrier concentration of the amorphous oxide can be controlled.

Claims

1. A field effect transistor comprising:

a channel layer of an amorphous oxide film containing In or Zn,

wherein the amorphous oxide film contains hydrogen or deuterium at a concentration in the range of 10¹⁶ to 10²⁰/cm³, and

wherein the composition of the amorphous oxide film containing hydrogen or deuterium is represented by the following equation that excludes the hydrogen;

[(Sn_1-xM4)O₂]_a.[(In_1-yM3_y)₂O₃]b.[Zn_1-zM2_z]]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 hold,

M4 is an element (Si Ge, or Zr) of Group IV having an atomic number smaller than that of Sn,

M3 is Lu or an element (B, Al, Ga, or Y) of Group III having an atomic number smaller than that of In, and

M2 is an element (Mg or Ca) of Group II having an atomic number smaller than that of Zn.

4. The field effect transistor according to claim 1,

wherein the M3 comprises Ga.

2. (canceled)

3. The field effect transistor according to claim 2,

wherein the concentration of hydrogen or deuterium contained in the amorphous oxide film is in the range of 10¹⁷ to 10¹⁹/cm³.

5. A method for manufacturing an amorphous oxide film which contains In or Zn and which is used as a channel layer of a field effect transistor, the method comprising the steps of:

disposing a substrate in a film-forming apparatus; and

forming the amorphous oxide film on the substrate while an oxygen gas and a gas (other than water vapor) containing hydrogen atoms are introduced in the film-forming apparatus at respective predetermined partial pressures.

6. The method for manufacturing an amorphous oxide film, according to claim 5,

wherein the amorphous oxide film is formed by a sputtering method, and the oxygen partial pressure during the step of forming the amorphous oxide film is 0.01 Pa or more.

7. A manufacturing apparatus for manufacturing an amorphous oxide film which is formed on a substrate and which is used as a channel layer of a field effect transistor, the apparatus comprising:

a film-forming chamber;

evacuation means for evacuating the inside of the film-forming chamber;

substrate holding means for holding the substrate in the film-forming chamber;

a material source disposed to face the substrate holding means;

an energy source for evaporating a material of the material source;

means for supplying a hydrogen gas in the film-forming chamber; and

means for supplying an oxygen gas in the film-forming chamber.

8. A method for manufacturing a field effect transistor, comprising the steps of:

forming a gate electrode;

forming a gate insulating layer;

forming a source electrode and a drain electrode; and

forming a channel layer of an amorphous oxide while an oxygen gas and a gas (other than water vapor) containing hydrogen atoms are introduced in a film-forming apparatus at respective predetermined partial pressures.

9. A method for manufacturing a field effect transistor, comprising the steps of:

forming a gate electrode;

forming a gate insulating layer;

forming a source electrode and a drain electrode;

forming a channel layer of an amorphous oxide in an atmosphere containing oxygen at a partial pressure of 0.01 Pa or more by a sputtering method; and

increasing the amount of hydrogen contained in the channel layer formed of the amorphous oxide.

10. A field effect transistor having a channel layer of an amorphous oxide film containing Zn and In,

wherein the amorphous oxide film contains hydrogen or deuterium.