SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20130193433A1
• Filed: 01/24/2013
• Published: 08/01/2013
• Est. Priority Date: 01/26/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Granted Patent: US 9,184,160 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 27/0629 in combination with diodes, or resistors, or capacitors
• CPC Class Codes: H01L 27/1222 with a particular composition, shape or crystalline structure of the active 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 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• 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 29/78651 Silicon transistors H01L29/78606 - H01L29/78645 take precedence
• CPC Class Codes: H01L 29/78681 having a semiconductor body comprising AIIIBV or AIIBVI or AIVBVI semiconductor materials, or Se or Te
• CPC Class Codes: H01L 29/78684 having a semiconductor body comprising semiconductor materials of Group IV not being silicon, or alloys including an element of the group IV, e.g. Ge, SiN alloys, SiC alloys H01L29/7869 takes precedence
• 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: H10B 41/70 the floating gate being an electrode shared by two or more components

Abstract

A semiconductor device having high electric characteristics and in which a capacitor is efficiently formed even if the semiconductor device has a miniaturized structure. In a top-gate (also referred to as staggered) transistor using an oxide semiconductor film as its active layer, a source electrode and a drain electrode has a two-layer structure (a first electrode film and a second electrode film). Then, a capacitor is formed using a film formed using a material and a step similar to those of the first electrode film, a gate insulating film, and a gate electrode. Accordingly, the transistor and the capacitor can be formed through the same process efficiently. Further, the second electrode is connected onto the oxide semiconductor film between a first electrode and a channel formation region of the transistor. Accordingly, resistance between source and drain electrodes can be reduced; therefore, electric characteristics of the semiconductor device can be improved.

Claims

1. A semiconductor device comprising a transistor and a capacitor,

the transistor comprising:

an oxide semiconductor film over an insulating surface;

a gate insulating film over the oxide semiconductor film;

a gate electrode over the gate insulating film;

a first electrode film covering an end portion of the oxide semiconductor film, and in direct contact with the end portion of the oxide semiconductor film; and

a second electrode film over the first electrode film, and electrically connected to the first electrode film and the oxide semiconductor film,

the capacitor comprising;

a lower electrode film;

an insulating film over the lower electrode film; and

an upper electrode film over the insulating film,

wherein the first electrode film and the lower electrode film are over and in direct contact with a same surface.

2. The semiconductor device according to claim 1, further comprising a second transistor under the transistor,

wherein an active layer of the second transistor comprises silicon, germanium, or a compound semiconductor material, and

wherein the second transistor is electrically connected to at least the transistor or the capacitor.

3. The semiconductor device according to claim 2, wherein the active layer of the second transistor comprises a film obtained using separation of part of a single crystal semiconductor substrate or a compound semiconductor substrate.

4. The semiconductor device according to claim 2, wherein the second transistor is positioned over a flexible substrate, and wherein the transistor is positioned over the second transistor.

5. The semiconductor device according to claim 1, wherein the oxide semiconductor film includes indium, gallium and zinc.

6. The semiconductor device according to claim 1, wherein the same surface is the insulating surface.

7. The semiconductor device according to claim 1, wherein the insulating film is same as the gate insulating film, and the upper electrode film is same as the gate electrode.

8. The semiconductor device according to claim 1, wherein the semiconductor device is one selected from the group consisting of a portable personal computer, an e-book reader, a smartphone, a digital video camera and a television set.

9. A semiconductor device comprising a transistor, the transistor comprising:

an oxide semiconductor film over an insulating surface;

a gate insulating film over the oxide semiconductor film;

a gate electrode over the gate insulating film;

a first electrode film covering an end portion of the oxide semiconductor film and in direct contact with the end portion of the oxide semiconductor film; and

a second electrode film over and in direct contact with the first electrode film,

wherein a portion of the second electrode film is in direct contact with a portion of the oxide semiconductor film.

10. The semiconductor device according to claim 9, further comprising a second transistor under the transistor,

wherein an active layer of the second transistor comprises silicon, germanium, or a compound semiconductor material, and

wherein the second transistor is electrically connected to the transistor.

11. The semiconductor device according to claim 10, wherein the active layer of the second transistor comprises a film obtained using separation of part of a single crystal semiconductor substrate or a compound semiconductor substrate.

12. The semiconductor device according to claim 10, wherein the second transistor is positioned over a flexible substrate, and wherein the transistor is positioned over the second transistor.

13. The semiconductor device according to claim 9, wherein the oxide semiconductor film includes indium, gallium and zinc.

14. The semiconductor device according to claim 9, wherein the semiconductor device is one selected from the group consisting of a portable personal computer, an e-book reader, a smartphone, a digital video camera and a television set.

15. A method for manufacturing a semiconductor device including a transistor and a capacitor, comprising the steps of:

forming an oxide semiconductor film over an insulating surface;

forming a first electrode film covering an end portion of the oxide semiconductor film an lower electrode film of the capacitor through a same step;

forming a gate insulating film over the oxide semiconductor film and an insulating film of the capacitor over the lower electrode film through a same step;

forming a gate electrode over the gate insulating film and an upper electrode film of the capacitor over the insulating film through a same step;

forming a second insulating film covering at least a side surface of the gate electrode, and

forming a second electrode film electrically connected to the first electrode film and the oxide semiconductor film.

16. The method for manufacturing a semiconductor device according to claim 15, further comprising a step of forming a second transistor,

wherein an active layer of the second transistor comprises silicon, germanium, or a compound semiconductor material,

wherein the transistor is positioned over the second transistor, and

wherein the second transistor is electrically connected to at least the transistor or the capacitor.

17. The method for manufacturing a semiconductor device according to claim 16, wherein the active layer of the second transistor comprises a film obtained using separation of part of a single crystal semiconductor substrate or a compound semiconductor substrate.

18. The method for manufacturing a semiconductor device according to claim 16, wherein the second transistor is positioned over a flexible substrate.