Display

• US 8,237,166 B2
• Filed: 08/02/2010
• Issued: 08/07/2012
• 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: Kumomi, Hideya, Hosono, Hideo, Kamiya, Toshio, Nomura, Kenji
• Primary Examiner(s): Yang, Minchul
• Application Number:
  US12/848,671
• Publication Number:
  US 20100295041A1
• Time in Patent Office: 736 Days
• Field of Search: 257/43, 257/52, 257/57, 257/59, 257/E29.083, 257/92, 257/101
• US Class Current: 257/59
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• 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

An active matrix display comprising a light control device and a field effect transistor for driving the light control device. The active layer of the field effect transistor comprises an amorphous.

Claims

1. An active matrix display comprising:

an electroluminescent device; and

a field effect transistor for driving the electroluminescent device having an active layer,

wherein the active layer of the field effect transistor comprises an amorphous oxide wherein;

(a) the amorphous oxide of the active layer is selected from the group consisting of an oxide containing In, Ga and Zn, an oxide containing In, Zn and Sn, an oxide containing In and Zn, an oxide containing In and Sn, and an oxide containing In; and

wherein

(b) the amorphous oxide has an electron carrier concentration of 10¹²/cm³ or more and less than 10¹⁸/cm³, and wherein a current between drain and source terminals of the field effect transistor when no gate voltage is applied is less than 10 microamperes; and

wherein

(c) the amorphous oxide has an oxygen defect density decreased by treatment in an atmosphere containing oxygen at a predetermined pressure upon or after film formation thereof.

2. The active matrix display according to claim 1, wherein the field effect transistor is such that a current and a voltage between the drain and source terminals when no gate voltage is applied and (transistor length/transistor width) satisfy I_DS<

(W/L)×

V_DS×

(1.0×

10<sup>−

5</sup>/24) [A] when V_GS=0 [V], where L is a channel length and W is a channel width, and wherein the amorphous oxide has a halo pattern and shows no specific diffraction ray in an X-ray diffraction spectrum.

3. The active matrix display according to claim 2, wherein the current and the voltage between the drain and source terminals when no gate voltage is applied and (transistor length/transistor width) satisfy I_DS<

(W/L)×

V_DS×

(5.0×

10<sup>−

8</sup>/24) [A] when V_GS=0 [V], where L is the channel length and W is the channel width.

4. The active matrix display according to claim 1, wherein the amorphous oxide has an observable halo pattern, and shows no specific diffraction ray in an X-ray diffraction spectrum.

5. The active matrix display according to claim 1, wherein an electron mobility of the active layer tends to increase with increasing electron carrier concentration.

6. An active matrix display comprising:

an electroluminescent device; and

a field effect transistor for driving the electroluminescent device,

wherein an active layer of the field effect transistor comprises an amorphous oxide of a compound having

(a) a composition when in a crystalline state represented by In<sub>2−

x</sub>M3_xO₃ (Zn<sub>1−

y</sub>M2_yO)_m, wherein M2 is Mg or Ca;

M3 is B, Al, Ga or Y;

0≦

x≦

2;

0≦

y≦

1; and

m is zero or a natural number less than 6, or a mixture of said compounds;

(b) an electron carrier concentration of 10¹²/cm³ or more and less than 10¹⁸/cm³, wherein a current between drain and source terminals of the field effect transistor when no gate voltage is applied is less than 10 microamperes; and

(c) oxygen defect density decreased by treatment in an atmosphere containing oxygen at a predetermined pressure upon or after film formation thereof.

7. The active matrix display according to claim 6, wherein the amorphous oxide additionally contains at least one of Sn and a Group IV element selected from Si, Ge or Zr.

8. The active matrix display according to claim 6, wherein the amorphous oxide comprises an oxide containing In, Ga, and Zn.

9. The active matrix display according to claim 6, wherein the electroluminescent device is arranged on a flexible resin substrate.

10. The active matrix display according to claim 6, wherein the electroluminescent device is arranged on a light transmissive substrate.

11. The active matrix display according to claim 6, wherein the amorphous oxide has an observable halo pattern, and shows no specific diffraction ray in an X-ray diffraction spectrum.

12. The active matrix display according to claim 6, wherein an electron mobility of the active layer tends to increase with increasing electron carrier concentration.

13. An active matrix display comprising:

an organic electroluminescent device; and

a field effect transistor for driving the organic electroluminescent device,

wherein an active layer of the field effect transistor comprises an amorphous oxide that

(a) is selected from the group consisting of an oxide containing In, Ga and Zn, an oxide containing In, Zn and Sn, an oxide containing In and Zn, an oxide containing In and Sn, and an oxide containing In; and

(b) has an electron carrier concentration of 10¹²/cm³ or more and less than 10¹⁸/cm³, wherein a current between drain and source terminals of the field effect transistor when no gate voltage is applied is less than 10 microamperes; and

(c) has an oxygen defect density decreased by treatment in an atmosphere containing oxygen at a predetermined pressure upon or after film formation thereof.

14. The active matrix display according to claim 13, wherein the field effect transistor is such that a current and a voltage between the drain and source terminals when no gate voltage is applied and (transistor length/transistor width) satisfy I_DS<

(W/L)×

V_DS×

(1.0×

10<sup>−

5</sup>/24) [A] when V_GS=0 [V], where L is a channel length and W is a channel width, and wherein the amorphous oxide has a halo pattern and shows no specific diffraction ray in an X-ray diffraction spectrum.

15. The active matrix display according to claim 14, wherein the current and the voltage between the drain and source terminals when no gate voltage is applied and (transistor length/transistor width) satisfy I_DS<

(W/L)×

V_DS×

(5.0×

10<sup>−

8</sup>/24) [A] when V_GS=0 [V], where L is the channel length and W is the channel width.

16. The active matrix display according to claim 13, wherein the amorphous oxide has an observable halo pattern, and shows no specific diffraction ray in an X-ray diffraction spectrum.

17. The active matrix display according to claim 13, wherein an electron mobility of the active layer tends to increase with increasing electron carrier concentration.

18. An active matrix display comprising:

a light control device; and

a field effect transistor for driving the light control device,

wherein an active layer of the field effect transistor comprises an amorphous oxide that

(a) is selected from the group consisting of an oxide containing In, Ga and Zn, an oxide containing In, Zn and Sn, an oxide containing In and Zn, an oxide containing In and Sn, and an oxide containing In; and

(b) has an electron carrier concentration of 10¹²/cm³ or more and less than 10¹⁸/cm³, wherein a current between drain and source terminals of the field effect transistor when no gate voltage is applied is less than 10 microamperes; and

(c) has an oxygen defect density decreased by treatment in an atmosphere containing oxygen at a predetermined pressure upon or after film formation thereof.

19. The active matrix display according to claim 18, wherein the light control device comprises one of an electroluminescent device, a liquid crystal and an electrophoretic particle.

20. The active matrix display according to claim 18, wherein the field effect transistor is such that a current and a voltage between the drain and source terminals when no gate voltage is applied and (transistor length/transistor width) satisfy I_DS<

(W/L)×

V_DS×

(1.0×

10<sup>−

5</sup>/24) [A] when V_GS=0 [V], where L is a channel length and W is a channel width, and wherein the amorphous oxide has a halo pattern and shows no specific diffraction ray in an X-ray diffraction spectrum.

21. The active matrix display according to claim 20, wherein the current and the voltage between the drain and source terminals when no gate voltage is applied and (transistor length/transistor width) satisfy I_DS<

(W/L)×

V_DS×

(5.0×

10<sup>−

8</sup>/24) [A] when V_GS=0 [V], where L is the channel length and W is the channel width.

22. The active matrix display according to claim 18, wherein the amorphous oxide has an observable halo pattern, and shows no specific diffraction ray in an X-ray diffraction spectrum.

23. The active matrix display according to claim 18, wherein an electron mobility of the active layer tends to increase with increasing electron carrier concentration.

24. An active matrix display comprising:

a light control device; and

a field effect transistor for driving the light control device,

wherein an active layer of the field effect transistor comprises an amorphous oxide that

(a) has a composition when in a crystalline state represented by In<sub>2−

x</sub>M3_xO₃ (Zn<sub>1−

y</sub>M2_yO)_m, wherein M2 is Mg or Ca;

M3 is B, Al, Ga or Y;

0≦

x≦

2;

0≦

y≦

1; and

m is zero or a natural number less than 6, or a mixture of said compounds; and

(b) has an electron carrier concentration of 10¹²/cm³ or more and less than 10¹⁸/cm³, wherein a current between drain and source terminals of the field effect transistor when no gate voltage is applied is less than 10 microamperes; and

(c) has an oxygen defect density decreased by treatment in an atmosphere containing oxygen at a predetermined pressure upon or after film formation thereof.

25. The active matrix display according to claim 24, wherein the field effect transistor is such that a current and a voltage between the drain and source terminals when no gate voltage is applied and (transistor length/transistor width) satisfy I_DS<

(W/L)×

V_DS×

(1.0×

10<sup>−

5</sup>/24) [A] when V_GS=0 [V], where L is a channel length and W is a channel width, and wherein the amorphous oxide has a halo pattern and shows no specific diffraction ray in an X-ray diffraction spectrum.

26. The active matrix display according to claim 25, wherein the current and the voltage between the drain and source terminals when no gate voltage is applied and (transistor length/transistor width) satisfy I_DS<

(W/L)×

V_DS×

(5.0×

10<sup>−

8</sup>/24) [A] when V_GS=0 [V], where L is the channel length and W is the channel width.

27. The active matrix display according to claim 24, wherein the amorphous oxide has an observable halo pattern, and shows no specific diffraction ray in an X-ray diffraction spectrum.

28. The active matrix display according to claim 24, wherein an electron mobility of the active layer tends to increase with increasing electron carrier concentration.

29. An active matrix display comprising:

an organic electroluminescent device; and

a field effect transistor for driving the organic electroluminescent device,

wherein an active layer of the field effect transistor comprises an amorphous oxide of a compound having

(a) a composition when in a crystalline state represented by In<sub>2−

x</sub>M3_xO₃ (Zn<sub>1−

y</sub>M2_yO)_m, wherein M2 is Mg or Ca;

M3 is B, Al, Ga or Y;

0≦

x≦

2;

0≦

y≦

1; and

m is zero or a natural number less than 6, or a mixture of said compounds;

(b) an electron carrier concentration of 10¹²/cm³ or more and less than 10¹⁸/cm³, wherein a current between drain and source terminals of the field effect transistor when no gate voltage is applied is less than 10 microamperes; and

(c) oxygen defect density decreased by treatment in an atmosphere containing oxygen at a predetermined pressure upon or after film formation thereof.

30. The active matrix display according to claim 29, wherein the field effect transistor is such that a current and a voltage between the drain and source terminals when no gate voltage is applied and (transistor length/transistor width) satisfy I_DS<

(W/L)×

V_DS×

(1.0×

10<sup>−

5</sup>/24) [A] when V_GS=0 [V], where L is a channel length and W is a channel width, and wherein the amorphous oxide has a halo pattern and shows no specific diffraction ray in an X-ray diffraction spectrum.

31. The active matrix display according to claim 30, wherein the current and the voltage between the drain and source terminals when no gate voltage is applied and (transistor length/transistor width) satisfy I_DS<

(W/L)×

V_DS×

(5.0×

10<sup>−

8</sup>/24) [A] when V_GS=0 [V], where L is the channel length and W is the channel width.

32. The active matrix display according to claim 29, wherein the amorphous oxide has an observable halo pattern, and shows no specific diffraction ray in an X-ray diffraction spectrum.

33. The active matrix display according to claim 29, wherein an electron mobility of the active layer tends to increase with increasing electron carrier concentration.