Field effect transistor

• US 7,906,780 B2
• Filed: 01/11/2007
• Issued: 03/15/2011
• Est. Priority Date: 01/30/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Iwasaki, Tatsuya
• Primary Examiner(s): Thai; Luan C
• Application Number:
  US12/097,850
• Publication Number:
  US 20090174012A1
• Time in Patent Office: 1,524 Days
• Field of Search: 257/347, 257/52, 257/59, 257/57, 257/E29.145, 257/E29.273
• US Class Current: 257/59
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• 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

Abstract

Provided is a field effect transistor, provided with a gate electrode 15, a source electrode 13, and a drain electrode 14 formed on a substrate, including a channel layer 11 formed of an oxide containing In, Zn, or Sn as the main component, and a gate insulating layer 12 provided between the channel layer 11 and the gate electrode 15, in which the gate insulating layer 12 is formed of an amorphous oxide containing Ga as the main component.

Claims

1. A field effect transistor that includes a gate electrode, a source electrode, and a drain electrode, the field effect transistor comprising:

a channel layer formed of an amorphous oxide semiconductor that includes In, Zn, and Ga; and

a gate insulating layer arranged between the channel layer and the gate electrode,

wherein the gate insulating layer is formed of an amorphous oxide that includes Ga as a main component and includes In and Zn.

2. A field effect transistor according to claim 1, wherein the amorphous oxide includes at least one element selected from a group consisting of In, Zn, and Sn.

3. A field effect transistor according to claim 1, wherein the amorphous oxide includes at least one element selected from a group consisting of Ti, Hf, Zr, Y, La, Nb, and Ta.

4. A field effect transistor according to claim 1,

wherein the channel layer is formed of an amorphous oxide expressed by (1):

((Sn_1-xM4_x)O₂)a.((In_1-YM3_Y)₂O₃)b.(Zn_1-zM2_zO)c 

 

(1),

wherein 0≦

x≦

1, 0≦

Y≦

1, 0≦

z≦

1, 0≦

a≦

1, 0≦

b≦

1, 0≦

c≦

1, and a+b+c=1,

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

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

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

5. A field effect transistor according to claim 4, wherein the channel layer is formed of an amorphous oxide expressed by one of (2) and (3):

((In_1-yGa_y)₂O₃)b.((ZnO))c 

 

(2),

wherein 0≦

y≦

1, 0≦

b≦

1, 0≦

c≦

1,

(SnO₂)a.((In₂O₃)b.((ZnO))c 

 

(3),

wherein 0≦

a≦

1, 0≦

b≦

1, 0≦

c≦

1.

6. A field effect transistor according to claim 5, wherein the channel layer is formed of an amorphous oxide that includes In as a main component and Ga as a sub component.

7. A field effect transistor that includes a gate electrode, a source electrode, and a drain electrode, the field effect transistor comprising:

a channel layer formed of an amorphous oxide semiconductor that includes In as a main component and includes Zn and Ga; and

a gate insulating layer arranged between the channel layer and the gate electrode,

wherein the gate insulating layer is formed of an amorphous oxide that includes Ga as a main component and includes In as a sub component.