Separation of thin GaN from sapphire by laser lift-off technique
Bibliographic Information
- Other Title
-
- Separation of thin GaN from sapphire by laser lift off technique
Search this article
Abstract
<jats:p> Laser lift-off of GaN from sapphire substrates has become a viable technique to increase the brightness of GaN-based light-emitting diodes (LEDs). The LEDs free from sapphire exhibit high luminous efficiency by placing highly reflective electrode on the back side. The devices serve low series resistance together with low thermal resistance taking advantages of the vertical structure. Thinner epitaxial structure is desired to serve better device performance, however, cracks in the film after the lift-off limits the minimum thickness. In this paper, successful laser lift-off of very thin GaN with the thickness down to 4 µm is described. The established laser lift-off system utilizes homogenized beam-profile of the employed neodymium-doped yttrium aluminium garnet (Nd:YAG) third harmonic laser in which optimization of the laser fluence minimizes the thickness of the decomposed GaN. It is also revealed by calculation that the compressive stress in the thin GaN is increased by reducing the thickness. It is demonstrated that the lattice of the GaN is relaxed after the laser lift-off, which is confirmed by photoluminescence (PL) and X-ray diffraction (XRD) measurements. In addition, reduction of the wafer bowing of GaN on sapphire is experimentally confirmed after the laser irradiation with the formation of metal Ga in between the interface. </jats:p>
Journal
-
- Japanese journal of applied physics : JJAP
-
Japanese journal of applied physics : JJAP 50 (4), 041001-, 2011-04
Tokyo : The Japan Society of Applied Physics
- Tweet
Details 詳細情報について
-
- CRID
- 1520290883368240128
-
- NII Article ID
- 40018800865
-
- NII Book ID
- AA12295836
-
- ISSN
- 00214922
- 13474065
-
- NDL BIB ID
- 11075332
-
- Text Lang
- en
-
- NDL Source Classification
-
- ZM35(科学技術--物理学)
-
- Data Source
-
- NDL
- Crossref
- CiNii Articles