Semiconductor device having first and second source and drain electrodes sandwiched between an island-shaped semiconductor film

• US 8,222,098 B2
• Filed: 06/28/2010
• Issued: 07/17/2012
• Est. Priority Date: 10/14/2005
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Honda, Tatsuya
• Primary Examiner(s): Lee, Hsien-ming
• Assistant Examiner(s): PARENDO, KEVIN A
• Application Number:
  US12/824,899
• Publication Number:
  US 20100264420A1
• Time in Patent Office: 750 Days
• Field of Search: 438/158, 438/161, 257/E51.005, 257/E51.006, 257/E29.151
• US Class Current: 438/158
• CPC Class Codes: H01L 29/41733 for thin film transistors with insulated gate
• 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: H10K 10/84 Ohmic electrodes, e.g. source or drain electrodes
• CPC Class Codes: H10K 2102/311 Flexible OLED
• CPC Class Codes: H10K 77/111 Flexible substrates
• CPC Class Codes: Y02E 10/549 Organic PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

An object is to obtain a semiconductor device with improved characteristics by reducing contact resistance of a semiconductor film with electrodes or wirings, and improving coverage of the semiconductor film and the electrodes or wirings. The present invention relates to a semiconductor device including a gate electrode over a substrate, a gate insulating film over the gate electrode, a first source or drain electrode over the gate insulating film, an island-shaped semiconductor film over the first source or drain electrode, and a second source or drain electrode over the island-shaped semiconductor film and the first source or drain electrode. Further, the second source or drain electrode is in contact with the first source or drain electrode, and the island-shaped semiconductor film is sandwiched between the first source or drain electrode and the second source or drain electrode. Moreover, the present invention relates to a manufacturing method of the semiconductor device.

Claims

1. A semiconductor device comprising:

a gate electrode over a substrate;

a gate insulating film over the gate electrode;

a first source or drain electrode over the gate insulating film;

an island-shaped semiconductor film including a channel forming region over the first source or drain electrode and the gate insulating film; and

a second source or drain electrode over the island-shaped semiconductor film and the first source or drain electrode,

wherein a part of the second source or drain electrode is formed over and directly in contact with the first source or drain electrode,

wherein the island-shaped semiconductor film is sandwiched between the first source or drain electrode and the second source or drain electrode, and

wherein the island-shaped semiconductor film is an inorganic semiconductor film including indium.

2. The semiconductor device according to claim 1, wherein the inorganic semiconductor film is any one from a group consisting of an indium oxide film, an indium phosphorus film and an indium nitride film.

3. The semiconductor device according to claim 1, wherein the first source or drain electrode is a titanium film.

4. The semiconductor device according to claim 1, wherein the gate electrode and the first source or drain electrode are formed of a same material.

5. The semiconductor device according to claim 1, wherein the gate electrode, the first source or drain electrode, and the second source or drain electrode are formed of a same material.

6. A semiconductor device comprising:

a gate electrode over a substrate;

a gate insulating film over the gate electrode;

a first source or drain electrode over the gate insulating film;

an island-shaped semiconductor film including a channel forming region over the first source or drain electrode and the gate insulating film;

an island-shaped impurity semiconductor film added with an impurity imparting one conductivity type over the island-shaped semiconductor film; and

a second source or drain electrode over the island-shaped semiconductor film, the island-shaped impurity semiconductor film, and the first source or drain electrode,

wherein a part of the second source or drain electrode is formed over and directly in contact with the first source or drain electrode,

wherein the island-shaped semiconductor film and the island-shaped impurity semiconductor film are sandwiched between the first source or drain electrode and the second source or drain electrode, and

wherein the island-shaped semiconductor film is an inorganic semiconductor film including indium.

7. The semiconductor device according to claim 6, wherein the inorganic semiconductor film is any one from a group consisting of an indium oxide film, an indium phosphorus film and an indium nitride film.

8. The semiconductor device according to claim 6, wherein the impurity imparting one conductivity type is phosphorus or arsenic.

9. The semiconductor device according to claim 6, wherein the impurity imparting one conductivity type is boron.

10. The semiconductor device according to claim 6, wherein the first source or drain electrode is a titanium film.

11. The semiconductor device according to claim 6, wherein the gate electrode and the first source or drain electrode are formed of a same material.

12. The semiconductor device according to claim 6, wherein the gate electrode, the first source or drain electrode, and the second source or drain electrode are formed of a same material.

13. A manufacturing method of a semiconductor device comprising the steps of:

forming a gate electrode over a substrate;

forming a gate insulating film over the gate electrode;

forming first source or drain electrode over the gate insulating film;

forming an island-shaped semiconductor film including a channel forming region over the first source or drain electrode and the gate insulating film; and

forming a second source or drain electrode over the first source or drain electrode and the island-shaped semiconductor film,

wherein a part of the second source or drain electrode is formed over and directly in contact with the first source or drain electrode,

wherein the island-shaped semiconductor film is sandwiched between the first source or drain electrode and the second source or drain electrode, and

wherein the island-shaped semiconductor film is an inorganic semiconductor film including indium.

14. The manufacturing method of a semiconductor device according to claim 13, wherein the first source or drain electrode is a titanium film.

15. The manufacturing method of a semiconductor device according to claim 13, wherein the gate electrode and the first source or drain electrode are formed of a same material.

16. The manufacturing method of a semiconductor device according to claim 13, wherein the gate electrode, the first source or drain electrode, and the second source or drain electrode are formed of a same material.

17. A manufacturing method of a semiconductor device comprising the steps of:

forming a first conductive film over a substrate;

forming a gate electrode using the first conductive film;

forming a gate insulating film over the gate electrode;

forming a second conductive film over the gate insulating film;

forming a first source or drain electrode using the second conductive film;

forming a semiconductor film over the first source or drain electrode;

forming an island-shaped semiconductor film including a channel forming region by patterning the semiconductor film;

forming a third conductive film over the first source or drain electrode and the island-shaped semiconductor film; and

forming a second source or drain electrode by patterning the third conductive film,

wherein a part of the second source or drain electrode is formed over and directly in contact with the first source or drain electrode,

wherein the island-shaped semiconductor film is sandwiched between the first source or drain electrode and the second source or drain electrode, and

wherein the island-shaped semiconductor film is an inorganic semiconductor film including indium.

18. The manufacturing method of a semiconductor device according to claim 17, wherein the first source or drain electrode is a titanium film.

19. The manufacturing method of a semiconductor device according to claim 17, wherein the gate electrode and the first source or drain electrode are formed of a same material.

20. The manufacturing method of a semiconductor device according to claim 17, wherein the gate electrode, the first source or drain electrode the second source or drain electrode are formed of a same material.

21. A manufacturing method of a semiconductor device comprising the steps of:

forming a gate electrode over a substrate;

forming a gate insulating film over the gate electrode;

forming a first source or drain electrode over the gate insulating film;

forming an island-shaped semiconductor film including a channel forming region over the first source or drain electrode and the gate insulating film;

forming an island-shaped impurity semiconductor film added with an impurity imparting one conductivity type over the island-shaped semiconductor film; and

forming a second source or drain electrode over the first source or drain electrode, the island-shaped semiconductor film, and the island-shaped impurity semiconductor film,

wherein a part of the second source or drain electrode is formed over and directly in contact with the first source or drain electrode,

wherein the island-shaped semiconductor film and the island-shaped impurity semiconductor film are sandwiched between the first source or drain electrode and the second source or drain electrode,

wherein the island-shaped semiconductor film is an inorganic semiconductor film including indium.

22. The manufacturing method of a semiconductor device according to claim 21, wherein the first source or drain electrode is a titanium film.

23. The manufacturing method of a semiconductor device according to claim 21, wherein the gate electrode and the first source or drain electrode are formed of a same material.

24. The manufacturing method of a semiconductor device according to claim 21, wherein the gate electrode, the first source or drain electrode, and the second source or drain electrode are formed of a same material.