US 12,155,004 B2
Method of separating plurality of LED structures from wafer
Young Rag Do, Seoul (KR)
Assigned to KOOKMIN UNIVERSITY INDUSTRY ACADEMY COOPERATION FOUNDATION, Seoul (KR)
Filed by KOOKMIN UNIVERSITY INDUSTRY ACADEMY COOPERATION FOUNDATION, Seoul (KR)
Filed on Dec. 28, 2021, as Appl. No. 17/563,393.
Claims priority of application No. 10-2020-0189204 (KR), filed on Dec. 31, 2020.
Prior Publication US 2022/0209043 A1, Jun. 30, 2022
Int. Cl. H01L 33/00 (2010.01)
CPC H01L 33/0093 (2020.05) 15 Claims
OG exemplary drawing
 
1. A method of separating a plurality of light-emitting diode (LED) structures from an LED wafer on which the plurality of LED structures are formed, wherein the plurality of LED structures include a second portion of a doped n-type III-nitride semiconductor layer and the second portion is formed on and connected to a first portion of the doped n-type III-nitride semiconductor layer, the method comprising:
operation (1) of forming a protective film so as to surround an exposed surface of each of the plurality of LED structures but expose an upper surface of the first portion between adjacent LED structures to the outside;
operation (2) of immersing the LED wafer in an electrolyte, electrically connecting one terminal of a power supply to the LED wafer and the other terminal of the power supply to an electrode immersed in the electrolyte, and applying power to form a plurality of pores in the first portion; and
operation (3) of applying ultrasonic waves to the LED wafer to separate the plurality of LED structures from the first portion in which the plurality of pores are formed.