| Autor: |
Haris Osman, Nga P. Pham, Vasyl Motsnyi, Cindy Demeulemeester, Maarten Rosmeulen, Deniz Sabuncuoglu Tezcan |
| Rok vydání: |
2011 |
| Předmět: |
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| Zdroj: |
International Symposium on Microelectronics. 2011:000130-000135 |
| ISSN: |
2380-4505 |
| DOI: |
10.4071/isom-2011-ta4-paper3 |
| Popis: |
This paper focuses on the substrate transfer process which is applied after the fabrication of LEDs on 4 inch Si (111) wafers comprising p and n contact formation to the GaN layer. After applying a passivation layer, a bonding metal is deposited. The wafer is then bonded to a Si carrier substrate using metallic bonding. Next, the original Si (111) substrate is completely removed by grinding and wet etching. GaN-LEDs are thus transferred to a new carrier substrate. The last step is etching of the transferred GaN layer from the back to open the contacts. A surface roughening technique on the backside of the transferred GaN layer to improve the light extraction efficiency of GaN-LEDs is also investigated. All the issues of the substrate transfer process steps such as permanent Cu/Sn bonding, thinning by grinding and wet etching will be discussed in detailed. A typical issue occurring during processing of GaN-LEDs on Si substrates is high stress and related large wafer bow originating from the GaN layer and the thick Cu/Sn metal bonding layer. Such a large wafer bow causes problems for some automatic handling tools and processes like lithography. Solutions to manage the stress and wafer bow have been investigated. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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