Method of laser irradiation, laser irradiation apparatus, and method of manufacturing a semiconductor device

• US 9,564,323 B2
• Filed: 04/09/2014
• Issued: 02/07/2017
• Est. Priority Date: 08/27/2001
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Moriwaka, Tomoaki, Tanaka, Koichiro
• Primary Examiner(s): Heinrich, Samuel M
• Application Number:
  US14/248,425
• Publication Number:
  US 20140220768A1
• Time in Patent Office: 1,035 Days
• Field of Search: 438/487, 359/618, 359/641, 219/121.66, 219/121.75
• US Class Current: 1/1
• CPC Class Codes: B23K 26/06 Shaping the laser beam, e.g. by masks or multi-focusing
• CPC Class Codes: B23K 26/0604 by a combination of beams
• CPC Class Codes: B23K 26/064 by means of optical elements, e.g. lenses, mirrors or prisms
• CPC Class Codes: B23K 26/0732 into a rectangular shape
• CPC Class Codes: B23K 26/0736 into an oval shape, e.g. elliptic shape
• CPC Class Codes: B23K 26/0738 into a linear shape
• CPC Class Codes: G02B 27/09 Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for adapting the beam shape of a laser diode G02B19/0052; adapting the beam shape of an LED G02B19/0061; coupling into light guides using intermediate optical elements G02B6/4204; beam shaping specially adapted for lasers H01S3/005
• CPC Class Codes: G02B 27/095 Refractive optical elements
• CPC Class Codes: G02B 27/0955 Lenses lenses per se G02B3/00
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02678 Beam shaping, e.g. using a mask
• CPC Class Codes: H01L 21/02683 Continuous wave laser beam
• CPC Class Codes: H01L 21/02686 Pulsed laser beam
• CPC Class Codes: H01L 21/268 using electromagnetic radiation, e.g. laser radiation
• CPC Class Codes: H01L 21/28017 the insulator being formed after the semiconductor body, the semiconductor being silicon
• 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 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01S 3/005 Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping shaping laser beam for working metal or other materials B23K26/06; optical elements, systems or apparatus in general G02B
• CPC Class Codes: H01S 5/4012 Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms
• CPC Class Codes: H01S 5/4025 : Array arrangements, e.g. constituted by discrete laser diodes or laser bar H01S5/42 takes precedence
• CPC Class Codes: H10K 50/84 : Passivation; Containers; Encapsulations
• CPC Class Codes: H10K 50/8426 : Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 59/12 : Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/122 : Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/87 : Passivation; Containers; Encapsulations

Abstract

If an optical path length of an optical system is reduced and a length of a laser light on an irradiation surface is increased, there occurs curvature of field which is a phenomenon that a convergent position deviates depending on an incident angle or incident position of a laser light with respect to a lens. To avoid this phenomenon, an optical element having a negative power such as a concave lens or a concave cylindrical lens is inserted to regulate the optical path length of the laser light and a convergent position is made coincident with a irradiation surface to form an image on the irradiation surface.

Claims

1. A method of manufacturing a semiconductor device comprising:

homogenizing an energy distribution of a laser beam along a first direction perpendicular to a propagation direction of the laser beam by utilizing at least a first cylindrical lens array and a second cylindrical lens array;

homogenizing an energy distribution of the laser beam along a second direction perpendicular to the propagation direction of the laser beam by utilizing at least a third cylindrical lens array and a fourth cylindrical lens array, wherein the second direction is perpendicular to the first direction;

condensing the laser beam along a third direction perpendicular the first direction by utilizing at least a doublet cylindrical lens;

irradiating a semiconductor film with the condensed laser beam to increase crystallinity of the semiconductor film while changing a relative location of the semiconductor film with respect to the condensed laser beam; and

patterning the semiconductor film into a plurality of semiconductor layers,

wherein each of the first cylindrical lens array and the second cylindrical lens array has a longitudinal direction along the second direction, and

wherein each of the third cylindrical lens array and the fourth cylindrical lens array has a longitudinal direction along the first direction.

2. The method according to claim 1, further comprising steps of:

forming a gate insulating film over at least one of the plurality of semiconductor layers; and

forming a gate electrode over the one of the plurality of semiconductor layers with the gate insulating film interposed therebetween.

3. The method according to claim 1, wherein the semiconductor film comprises amorphous silicon and is crystallized by the step of irradiating with the condensed laser beam.

4. The method according to claim 1, wherein the laser beam is emitted by an excimer laser.

5. A method of manufacturing a semiconductor device comprising:

homogenizing an energy distribution of a laser beam along a first direction perpendicular to a propagation direction of the laser beam by utilizing at least a first cylindrical lens array, a second cylindrical lens array and a first cylindrical lens;

homogenizing an energy distribution of the laser beam along a second direction perpendicular to the propagation direction of the laser beam by utilzing at least a third cylindrical lens array, a fourth cylindrical lens array and a second cylindrical lens, wherein the second direction is perpendicular to the first direction;

condensing the laser beam along a third direction perpendicular the first direction by utilizing at least a doublet cylindrical lens;

irradiating a semiconductor film with the condensed laser beam to increase crystallinity of the semiconductor film while changing a relative location of the semiconductor film with respect to the condensed laser beam; and

patterning the semiconductor film into a plurality of semiconductor layers,

wherein each of the first cylindrical lens array and the second cylindrical lens array has a longitudinal direction along the second direction, and

wherein each of the third cylindrical lens array and the fourth cylindrical lens array has a longitudinal direction along the first direction.

6. The method according to claim 5, further comprising steps of:

forming a gate insulating film over at least one of the plurality of semiconductor layers; and

forming a gate electrode over the one of the plurality of semiconductor layers with the gate insulating film interposed therebetween.

7. The method according to claim 5, wherein the semiconductor film comprises amorphous silicon and is crystallized by the step of irradiating with the condensed laser beam.

8. The method according to claim 5, wherein the laser beam is emitted by an excimer laser.