Method of manufacturing semiconductor element

Patent metadata

Field	Value
Publication number	US-2018247871-A1
Application number	US-201815902756-A
Country	US
Kind code	A1
Filing date	Feb 22, 2018
Priority date	Feb 27, 2017
Publication date	Aug 30, 2018
Grant date	—

Abstract

A method of manufacturing a semiconductor element includes: providing a wafer having a semiconductor layered body on a sapphire substrate; irradiating a laser light in an interior region of the sapphire substrate to create cracks in the sapphire substrate by performing a first scan to irradiate the laser light at a first depth with a first pulse energy to create a first modified region, and a second scan following the first scan to irradiate the laser light at a second depth with a second pulse energy greater than the first pulse energy along and within the first modified region; and dividing the wafer by extending the cracks to obtain a semiconductor element.

First claim

What is claimed is:

1 . A method of manufacturing a semiconductor element comprising:
providing a wafer having a semiconductor layered body on a sapphire substrate; irradiating a laser light in an interior region of the sapphire substrate to create cracks in the sapphire substrate by performing
a first scan to irradiate the laser light at a first depth with a first pulse energy to create a first modified region, and
a second scan following the first scan to irradiate the laser light at a second depth with a second pulse energy greater than the first pulse energy along and within the first modified region; and
dividing the wafer by extending the cracks to obtain a semiconductor element.

2 . The method of manufacturing a semiconductor element according to claim 1 , wherein
the second pulse energy with respect to the first pulse energy is in a range of 110% to 300%.

3 . The method of manufacturing a semiconductor element according to claim 1 , wherein
the first scan and the second scan are carried out along a m-axis of sapphire used for the sapphire substrate.

4 . The method of manufacturing a semiconductor element according to claim 1 , wherein
the first scan and the second scan are carried out along an a-axis of sapphire used for the sapphire substrate.

5 . The method of manufacturing a semiconductor element according to claim 4 , wherein
the first scan is a first a-axis direction scan with a first spot interval, and the second scan is a second a-axis direction scan with a second spot interval that is smaller than the first spot interval.

6 . The method of manufacturing a semiconductor element according to claim 5 , wherein
the second spot interval with respect to the first spot interval is in a range of 20% to 80%.

7 . The method of manufacturing a semiconductor element according to claim 5 , wherein
the irradiating of the laser light further includes performing
a first m-axis direction scan to irradiate the laser light at a third depth along a m-axis of the sapphire with a third spot interval and a third pulse energy to create a third modified region, and
a second m-axis direction scan following the first m-axis direction scan to irradiate the laser light at a fourth depth along the m-axis within a third modified region with a fourth spot interval and a fourth pulse energy greater than the third pulse energy.

8 . The method of manufacturing a semiconductor element according to claim 7 , wherein
the fourth spot interval is greater than the third spot interval.

9 . The method of manufacturing a semiconductor element according to claim 7 , wherein
the third spot interval is smaller than the first spot interval.

10 . The method of manufacturing a semiconductor element according to claim 7 , wherein
the first a-axis direction scan and the second a-axis direction scan are successively carried out such that the first a-axis direction scan is carried out from a first end to a second end of the wafer and the second a-axis direction scan is carried out from the second end to the first end of the wafer, and before or after the first a-axis direction scan and the second a-axis direction scan are carried out, the first m-axis direction scan and the second m-axis direction scan are successively carried out such that the first m-axis direction scan is carried out from the first end to the second end of the wafer and the second m-axis direction scan is carried out from the second end to the first end of the wafer.

11 . The method of manufacturing a semiconductor element according to claim 7 , wherein
the second a-axis direction scan is performed within 10 seconds after the first a-axis direction scan, and the second m-axis direction scan is performed within 10 seconds after the first m-axis direction scan.

12 . The method of manufacturing a semiconductor element according to claim 7 , wherein
scan speeds of the first a-axis direction scan, the second a-axis direction scan, the first m-axis direction scan, and the second m-axis direction scan are respectively set to allow a reciprocating scanning along a diameter of the wafer to complete within 10 seconds.

13 . The method of manufacturing a semiconductor element according to claim 7 , wherein
the fourth spot interval with respect to the third spot interval is in a range of 110% to 300%.

14 . The method of manufacturing a semiconductor element according to claim 7 , wherein
the forth pulse energy with respect to the third pulse energy is in a range of 110% to 300%.

15 . The method of manufacturing a semiconductor element according to claim 7 , wherein
the second pulse energy is smaller than the fourth pulse energy, and the second spot interval is smaller than the fourth spot interval.

16 . The method of manufacturing a semiconductor element according to claim 7 , wherein
the first pulse energy, the second pulse energy, the third pulse energy, and the fourth pulse energy are respectively within a range of 0.6 μJ to 10 μJ.

17 . The method of manufacturing a semiconductor element according to claim 7 , wherein
a pulse width of the laser light respectively used in the first a-axis direction scan, the second a-axis direction scan, the first m-axis direction scan, and the second m-axis direction scan is in a range of 100 fsec to 10 psec.

Assignees

• Nichia Corp

Inventors

• Inoue Naoto
• Kusaka Sho
• Yamamoto Minoru
• Ibaraki Masayuki
• Tamemoto Hiroaki

Classifications

• H10P54/00 Primary

  Cutting or separating of wafers, substrates or parts of devices · CPC title

• B23K26/53

  for modifying or reforming the material inside the workpiece, e.g. for producing break initiation cracks · CPC title

• B23K2103/56

  being semiconducting · CPC title

• H01L33/0095

  Electricity · mapped topic

• H01L21/78 Primary

  Electricity · mapped topic