Semiconductor device and method of manufacturing the semiconductor device

• US 20030178682A1
• Filed: 12/20/2002
• Published: 09/25/2003
• Est. Priority Date: 12/28/2001
• Status: Abandoned Application

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Miyairi, Hidekazu, Shiga, Aiko, Noda, Takeshi, Arao, Tatsuya, Kajiwara, Masayuki
• Application Number:
  US10/324,066
• Publication Number:
  US 20030178682A1
• Time in Patent Office: Days
• US Class Current: 257/368
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/1285 using control of the annealing or irradiation parameters, e.g. using different scanning direction or intensity for different transistors
• 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 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/66757 Lateral single gate single channel transistors with non-inverted structure, i.e. the channel layer is formed before the gate
• CPC Class Codes: H01L 29/78675 with normal-type structure, e.g. with top gate
• 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

An object is to form a crystalline semiconductor film having good crystallinity by applying a CW laser thereto, and to achieve a TFT capable of very high speed operation by using the semiconductor film thus obtained. A p-type impurity element is added to crystalline silicon (semiconductor layer), which has a film thickness of 60 to 400 nm and is formed by using a CW laser, in particular, to a channel formation region in a region that becomes an n-channel TFT. The p-type impurity element is added at an acceleration energy of 30 to 120 keV so that its concentration becomes 1×10¹⁵ to 5×10¹⁸ /cm³.

Claims

1. A semiconductor device comprising:

a semiconductor film on an insulating surface;

a gate insulating film over the semiconductor layer; and

a gate electrode over the gate insulating film,

wherein;

the semiconductor film comprises at least a channel formation region, a source region, and a drain region;

the channel formation region contains an impurity element at a concentration of 1×

10¹⁵ to 5×

10¹⁸/cm³;

a film thickness of the channel formation region is equal to or greater than 60 nm; and

a concentration peak of the impurity element is set to a region at a depth equal to or greater than 60 nm from a surface of the channel formation region.

2. A semiconductor device according to claim 1, wherein:

the impurity element contained in the channel formation region is an impurity element that imparts a p-type conductivity in a case of a channel formation region of an n-channel TFT.

3. A semiconductor device according to claim 1, wherein:

the impurity element contained in the channel formation region is an impurity element that imparts an n-type conductivity in a case of a channel formation region of a p-channel TFT.

4. A semiconductor device according to claim 1, wherein:

a thickness of the semiconductor film is equal to or less than 200 nm.

15. A semiconductor device according to claim 1, wherein the semiconductor device is applied to an electrical appliance selected from the group consisting of a video camera, a digital camera, a projector, a head mounted display, a personal computer, a mobile computer, a mobile phone and an electronic book.

5. A method of manufacturing a semiconductor device, comprising:

forming a semiconductor film having a thickness equal to or greater than 60 nm;

irradiating continuous wave laser to the semiconductor film to form an interface between a melted phase and a solid phase to form a crystalline semiconductor film; and

adding an impurity element to the crystalline semiconductor film,

wherein;

the impurity element is added so that a position of a concentration peak of the impurity element is at a depth equal to or greater than 60 nm in a depth direction of the crystalline semiconductor film.

7. A method of manufacturing a semiconductor device according to claim 5, wherein:

the addition of the impurity element is performed by an ion shower doping method, at an acceleration energy equal to or greater than 30 keV.

9. A method of manufacturing a semiconductor device according to claim 7 wherein:

the acceleration energy is equal to or less than 120 keV.

11. A method of manufacturing a semiconductor device according to claim 7 wherein:

the acceleration energy is equal to or less than 80 keV.

13. A method of manufacturing a semiconductor device according to claim 5, wherein:

the laser uses a solid laser oscillating apparatus as a light source, which is a second harmonic of an Nd;

YAG laser, an Nd;

YVO₄ laser, an Nd;

YLF laser, a Ti;

sapphire laser, or an alexandrite laser.

16. A method of manufacturing a semiconductor device according to claim 5, wherein the semiconductor device is applied to an electrical appliance selected from the group consisting of a video camera, a digital camera, a projector, a head mounted display, a personal computer, a mobile computer, a mobile phone and an electronic book.

6. A method of manufacturing a semiconductor device, comprising:

forming a semiconductor film having a thickness equal to or greater than 60 nm;

adding an impurity element to the semiconductor film; and

irradiating continuous wave laser to the semiconductor film to form an interface between a melted phase and a solid phase to form a crystalline semiconductor film,

wherein;

the impurity element is added so that a position of a concentration peak of the impurity element is at a depth equal to or greater than 60 nm in a depth direction of the crystalline semiconductor film.

8. A method of manufacturing a semiconductor device according to claim 6, wherein:

the addition of the impurity element is performed by an ion shower doping method, at an acceleration energy equal to or greater than 30 keV.

10. A method of manufacturing a semiconductor device according to claim 8 wherein:

the acceleration energy is equal to or less than 120 keV.

12. A method of manufacturing a semiconductor device according to claim 8 wherein:

the acceleration energy is equal to or less than 80 keV.

14. A method of manufacturing a semiconductor device according to claim 6, wherein:

the laser uses a solid laser oscillating apparatus as a light source, which is a second harmonic of an Nd;

YAG laser, an Nd;

YVO₄ laser, an Nd;

YLF laser, a Ti;

sapphire laser, or an alexandrite laser.

17. A method of manufacturing a semiconductor device according to claim 6, wherein the semiconductor device is applied to an electrical appliance selected from the group consisting of a video camera, a digital camera, a projector, a head mounted display, a personal computer, a mobile computer, a mobile phone and an electronic book.