Laser Irradiation Method, Laser Irradiation Apparatus, And Semiconductor Device

• US 20080254598A1
• Filed: 04/21/2008
• Published: 10/16/2008
• Est. Priority Date: 02/12/1999
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Tanaka, Koichiro, Yamazaki, Shunpei
• Granted Patent: US 7,981,733 B2
• Time in Patent Office: Days
• US Class Current: 438/473
• CPC Class Codes: G02B 19/0014 at least one surface having optical power
• CPC Class Codes: G02B 19/0052 the light source comprising a laser diode coupling into light guides using intermediate optical elements G02B6/4204; semiconductor lasers having optical devices external to the laser cavity H01S5/005
• CPC Class Codes: G02B 27/0911 Anamorphotic systems
• CPC Class Codes: G02B 27/0955 Lenses lenses per se G02B3/00
• CPC Class Codes: G02B 27/0961 Lens arrays lens arrays per se G02B3/0006
• CPC Class Codes: G02B 27/0966 Cylindrical lenses cylindrical lenses per se G02B3/06
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02488 Insulating materials
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02672 using crystallisation enhancing elements
• CPC Class Codes: H01L 21/02675 using laser beams
• CPC Class Codes: H01L 21/02686 Pulsed laser beam
• CPC Class Codes: H01L 21/02691 Scanning of a beam
• CPC Class Codes: H01L 27/1277 using a crystallisation promoting species, e.g. local introduction of Ni catalyst
• 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 27/1296 adapted to increase the uniformity of device parameters
• CPC Class Codes: H01L 29/78627 with a significant overlap between the lightly doped drain and the gate electrode, e.g. GOLDD

Abstract

An object of the present invention is obtaining a semiconductor film with uniform characteristics by improving irradiation variations of the semiconductor film. The irradiation variations are generated due to scanning while irradiating with a linear laser beam of the pulse emission. At a laser crystallization step of irradiating a semiconductor film with a laser light, a continuous light emission excimer laser emission device is used as a laser light source. For example, in a method of fabricating an active matrix type liquid crystal display device, a continuous light emission excimer laser beam is irradiated to a semiconductor film, which is processed to be a linear shape, while scanning in a vertical direction to the linear direction. Therefore, more uniform crystallization can be performed because irradiation marks can be avoided by a conventional pulse laser.

Claims

1-38. -38. (canceled)

39. A method of manufacturing a semiconductor device comprising:

providing a semiconductor film comprising crystalline silicon over a glass substrate;

irradiating the semiconductor film with a laser to cure defects of the semiconductor film,

wherein an output power Lw (W) of the laser and a spot size Sp (cm²) on an irradiated surface satisfy the following relationships,

Lw>

1×

10⁵Sp,

and

Sp>

2.5×

10<sup>−

5</sup>.

40. The method of manufacturing a semiconductor device according to claim 39, wherein a spot shape of the laser on the irradiated surface is a linear shape.

41. The method of manufacturing a semiconductor device according to claim 39, wherein the semiconductor film is provided over the glass substrate with an insulating film interposed therebetween.

42. The method of manufacturing a semiconductor device according to claim 39, wherein the laser is a continuous excimer laser.

43. The method of manufacturing a semiconductor device according to claim 39, further comprising a step of patterning the semiconductor film into a plurality of semiconductor layers as active layers of thin film transistors after the irradiation of the laser.

44. The method of manufacturing a semiconductor device according to claim 39 wherein the crystalline silicon is polycrystal silicon.

45. A method of manufacturing a semiconductor device comprising:

providing a semiconductor film comprising crystalline silicon over a glass substrate;

irradiating the semiconductor film with a laser to cure defects of the semiconductor film,

wherein an output power Lw (W) of the laser and a spot size Sp (cm²) on an irradiated surface satisfy the following relationships,

Lw>

2×

10⁵Sp,

and

Sp>

2.5×

10<sup>−

5</sup>.

46. The method of manufacturing a semiconductor device according to claim 45, wherein a spot shape of the laser on the irradiated surface is a linear shape.

47. The method of manufacturing a semiconductor device according to claim 45, wherein the semiconductor film is provided over the glass substrate with an insulating film interposed therebetween.

48. The method of manufacturing a semiconductor device according to claim 45, wherein the laser is a continuous excimer laser.

49. The method of manufacturing a semiconductor device according to claim 45, further comprising a step of patterning the semiconductor film into a plurality of semiconductor layers as active layers of thin film transistors after the irradiation of the laser.

50. The method of manufacturing a semiconductor device according to claim 45 wherein the crystalline silicon is polycrystal silicon.

51. A method of manufacturing a semiconductor device comprising:

providing a semiconductor film comprising crystalline silicon over a glass substrate;

irradiating the semiconductor film with a laser to cure defects of the semiconductor film,

wherein an output power Lw (W) of the laser and a spot size Sp (cm²) on an irradiated surface satisfy the following relationships,

Lw>

2×

10³Sp,

and

Sp>

2.5×

10<sup>−

5</sup>.

52. The method of manufacturing a semiconductor device according to claim 51, wherein a spot shape of the laser on the irradiated surface is a linear shape.

53. The method of manufacturing a semiconductor device according to claim 51, wherein the semiconductor film is provided over the glass substrate with an insulating film interposed therebetween.

54. The method of manufacturing a semiconductor device according to claim 51, wherein the laser is a continuous excimer laser.

55. The method of manufacturing a semiconductor device according to claim 51, further comprising a step of patterning the semiconductor film into a plurality of semiconductor layers as active layers of thin film transistors after the irradiation of the laser.

56. The method of manufacturing a semiconductor device according to claim 51 wherein the crystalline silicon is polycrystal silicon.