Highly effective transfer of micro-LED pixels to the intermediate and rigid substrate with weak and tunable adhesion by thiol modification
Journal article, 2023
Based on transfer printing technology, micro-LED pixels can be transferred to different types and sizes of driving substrates to realize displays with different application scenarios. To achieve a successful transfer, GaN-based micro-LEDs first need to be separated from the original epitaxial substrate. Here, micro-LED pixels (each size 25 μm × 30 μm) on the sapphire substrate were transferred to a flexible semiconductor wafer processing (SWP) tape that is strongly sticky by conventional laser lift-off (LLO) techniques. The pixels on the SWP tape were then transferred by using a sacrificial layer of non-crosslinked oligomeric polystyrene (PS) film onto the intermediate and rigid substrate (IRS) with weak and tunable adhesion by thiol (-SH) modification. The electrode of the micro-LED is Au metal, which forms Au-S bonds with the surface of the IRS to fix the pixels. The rigid substrate helps ensure that the pixel spacing is almost unchanged during the stamp transfer process, and the weak and tunable adhesion facilitates the pixels being picked up by the stamp. The experimental results demonstrate that the pixels can be efficiently transferred to the IRS by LLO and sacrificial layer-assistance, which will provide the possibility of achieving the further transfer of pixels to different types and sizes of driving substrates by a suitable transfer stamp. The transfer process details are discussed, which can provide insights into the transfer of micro-nano devices through polymer sacrificial layers.
Author
Kui Pan
Fuzhou University
Jie Sun
Fuzhou University
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Chang Lin
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Fuzhou University
Liying Deng
Fuzhou University
Xiao Li
Fuzhou University
Zuodong Mao
Fuzhou University
Tianxi Yang
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Zhonghang Huang
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Yang Li
Fuzhou University
Junyang Nie
Xi'an Jiaotong University
Tailiang Guo
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Fuzhou University
Qun Yan
Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China
Fuzhou University
Nanoscale
2040-3364 (ISSN) 2040-3372 (eISSN)
Vol. 15 9 4420-4428Subject Categories
Polymer Chemistry
Materials Chemistry
Condensed Matter Physics
DOI
10.1039/d2nr06021c