Semiconductor device and method for manufacturing semiconductor device

• US 9,337,342 B2
• Filed: 03/15/2013
• Issued: 05/10/2016
• Est. Priority Date: 04/13/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Okazaki, Kenichi, Miyamoto, Toshiyuki, Nomura, Masafumi, Hamochi, Takashi, Yamazaki, Shunpei, Sasaki, Toshinari
• Primary Examiner(s): Parker, Allen
• Assistant Examiner(s): MAZUMDER, DIDARUL A
• Application Number:
  US13/833,389
• Publication Number:
  US 20130270549A1
• Time in Patent Office: 1,152 Days
• Field of Search: 257/410, 257/411, 257/43, 257/64
• US Class Current: 1/1
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/47573 Etching the layer
• 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 27/1259 Multistep manufacturing methods
• 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 29/78696 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

In a semiconductor device including an oxide semiconductor, the amount of oxygen vacancies is reduced. Moreover, electrical characteristics of a semiconductor device including an oxide semiconductor are improved. The semiconductor device includes a transistor including a gate electrode over a substrate, a gate insulating film covering the gate electrode, an oxide semiconductor film overlapping with the gate electrode with the gate insulating film provided therebetween, and a pair of electrodes in contact with the oxide semiconductor film; and over the transistor, a first insulating film covering the gate insulating film, the oxide semiconductor film, and the pair of electrodes; and a second insulating film covering the first insulating film. An etching rate of the first insulating film is lower than or equal to 10 nm/min and lower than an etching rate of the second insulating film when etching is performed at 25° C. with 0.5 weight % of hydrofluoric acid.

Claims

1. A semiconductor device comprising:

a gate electrode over a substrate;

a gate insulating film covering the gate electrode;

an oxide semiconductor film overlapping with the gate electrode with the gate insulating film therebetween;

a pair of electrodes in contact with the oxide semiconductor film;

a first oxide insulating film covering the gate insulating film, the oxide semiconductor film, and the pair of electrodes; and

a second oxide insulating film covering the first oxide insulating film, the second oxide insulating film being thicker than the first oxide insulating film,

wherein an etching rate of the first oxide insulating film is lower than or equal to 10 nm/min and lower than an etching rate of the second oxide insulating film when etching is performed at 25°

C. with a solution of 0.5 weight % of hydrofluoric acid, and

wherein the first oxide insulating film and the second oxide insulating film are each a silicon oxide film or a silicon oxynitride film.

2. The semiconductor device according to claim 1,

wherein the second oxide insulating film contains oxygen at a higher proportion than a stoichiometric composition.

3. The semiconductor device according to claim 1,

wherein the gate insulating film is a silicon oxide film or a silicon oxynitride film.

4. The semiconductor device according to claim 1,

wherein spin densities of the oxide semiconductor film measured by electron spin resonance are less than or equal to a lower limit of detection at a g-factor of 1.93.

5. The semiconductor device according to claim 1, further comprising:

a blocking film over the second oxide insulating film, the blocking film comprising oxygen and any one of aluminum, gallium, yttrium, and hafnium.

6. The semiconductor device according to claim 1, wherein the first oxide insulating film and the second oxide insulating film are a first silicon oxynitride film and a second silicon oxynitride film, respectively.

7. The semiconductor device according to claim 1, further comprising a silicon nitride film covering the second oxide insulating film,

wherein the first oxide insulating film and the second oxide insulating film are a first silicon oxynitride film and a second silicon oxynitride film, respectively.

8. A semiconductor device comprising:

a transistor comprising;

a gate electrode over a substrate;

a gate insulating film covering the gate electrode;

an oxide semiconductor film overlapping with the gate electrode with the gate insulating film therebetween;

a pair of electrodes in contact with the oxide semiconductor film;

a first oxide insulating film covering the gate insulating film, the oxide semiconductor film, and the pair of electrodes; and

a second oxide insulating film over the first oxide insulating film, the second oxide insulating film being thicker than the first oxide insulating film,

wherein oxygen can be diffused into and from the first oxide insulating film,

wherein the second oxide insulating film contains oxygen at a higher proportion than a stoichiometric composition, and

wherein the first oxide insulating film and the second oxide insulating film are each a silicon oxide film or a silicon oxynitride film;

wherein an etching rate of the gate insulating film is lower than or equal to 10 nm/min and lower than the etching rate of the second oxide insulating film when etching is performed at 25°

C. with a solution of 0.5 weight % of hydrofluoric acid.

9. The semiconductor device according to claim 8,

wherein the gate insulating film is a silicon oxide film or a silicon oxynitride film.

10. The semiconductor device according to claim 8,

wherein spin densities of the oxide semiconductor film measured by electron spin resonance are less than or equal to a lower limit of detection at a g-factor of 1.93.

11. The semiconductor device according to claim 8, further comprising:

a blocking film over the second oxide insulating film, the blocking film comprising oxygen and any one of aluminum, gallium, yttrium, and hafnium.

12. The semiconductor device according to claim 8, wherein the first oxide insulating film and the second oxide insulating film are a first silicon oxynitride film and a second silicon oxynitride film, respectively.

13. The semiconductor device according to claim 8, further comprising a silicon nitride film covering the second oxide insulating film,

wherein the first oxide insulating film and the second oxide insulating film are a first silicon oxynitride film and a second silicon oxynitride film, respectively.

14. A semiconductor device comprising:

a gate electrode over a substrate;

a gate insulating film covering the gate electrode;

an oxide semiconductor film overlapping the gate electrode and on and in contact with the gate insulating film;

a pair of electrodes in contact with the oxide semiconductor film;

a first oxide insulating film covering the gate insulating film and the oxide semiconductor film;

a second oxide insulating film covering the first oxide insulating film, the oxide semiconductor film, and the pair of electrodes, the second oxide insulating film being thicker than the first oxide insulating film,

wherein an etching rate of the first oxide insulating film is lower than or equal to 10 nm/min and lower than an etching rate of the second oxide insulating film when etching is performed at 25°

C. with a solution of 0.5 weight % of hydrofluoric acid,

wherein the gate insulating film is formed from a first film comprising silicon and nitrogen and a second film comprising silicon and oxygen on and in contact with the first film and in contact with the oxide semiconductor film,

wherein the first oxide insulating film and the second oxide insulating film each comprise silicon, oxygen, and nitrogen, with more oxygen than nitrogen.

15. The semiconductor device according to claim 14,

wherein the second oxide insulating film contains oxygen at a higher proportion than a stoichiometric composition.

16. The semiconductor device according to claim 14,

wherein spin densities of the oxide semiconductor film measured by electron spin resonance are less than or equal to a lower limit of detection at a g-factor of 1.93.

17. The semiconductor device according to claim 14,

wherein the first oxide insulating film covers the pair of electrodes.

18. The semiconductor device according to claim 14, further comprising:

a blocking film over the second oxide insulating film, the blocking film comprising oxygen and any one of aluminum, gallium, yttrium, and hafnium.

19. The semiconductor device according to claim 14, wherein the first oxide insulating film and the second oxide insulating film are a first silicon oxynitride film and a second silicon oxynitride film, respectively.

20. The semiconductor device according to claim 14, further comprising a silicon nitride film covering the second oxide insulating film,

wherein the first oxide insulating film and the second oxide insulating film are a first silicon oxynitride film and a second silicon oxynitride film, respectively.

21. A semiconductor device comprising:

a gate electrode over a substrate;

an oxide semiconductor film overlapping with the gate electrode;

a gate insulating film between the gate electrode and the oxide semiconductor film;

a pair of electrodes in contact with the oxide semiconductor film; and

a stacked film of a first oxynitride film, a second oxynitride film, and a silicon nitride film, in this order, the first oxynitride film being on and in contact with the oxide semiconductor film,

wherein the second oxynitride film is thicker than the first oxynitride film, and

wherein an etching rate of the first oxynitride film is lower than or equal to 10 nm/min and lower than an etching rate of the second oxynitride film when etching is performed at 25°

C. with a solution of 0.5 weight % of hydrofluoric acid.