Improved Device Performance in AlGaN/GaN HEMT by Forming Ohmic Contact With Laser Annealing

Enhanced performance of flexible LED by low-temperature annealing

“…This needs to be done after the substrate transfer. However, after the transfer to a flexible substrate, high-temperature processes must be avoided in subsequent processes due to the large thermal mismatch stress between epitaxial thin-film and substrate [20,21,25], which consequently leads to the degraded electrical properties of flexible devices [26,27]. Therefore, low-temperature annealing is very necessary.…”

Au‐Free Ohmic Contacts and Their Impact on Sub‐Contact Charge Carrier Concentration in AlGaN/GaN Heterostructures

“…During the last two decades, the Ti/Al/Ni/Au contact metallization has emerged as the state-ofthe-art ohmic contact stack for such devices. [1] However, aiming for device integration in complementary metal-oxidesemiconductor compatible environments on large Si substrates [2][3][4] and to drastically reduce ohmic contact surface roughness, [5] as well as production costs, an Au-free contact metallization is required. Achieving low ohmic contacts with Au-free metallization is challenging, [1] thus, a more profound understanding of the Au-free ohmic contact formation mechanism is needed.…”

Mechanism of Ti/Al/Ni/Au ohmic contacts to AlGaN/GaN heterostructures via laser annealing

“…The ohmic contact formation process for AlGaN/GaN HEMTs based on pulsed laser annealing is reported in our previous work. [23] But a systematic investigation of the microstructure and physical mechanism of laser annealed ohmic contacts to AlGaN/GaN heterostructure is lacking. In this work, electrical measurements and a range of physical analysis tools including atomic force microscopy (AFM), focused ion beam (FIB), transmission electron microscopy (TEM), and energy dispersive x-ray spectroscopy (EDS) are used to investigate the morphology and composition of the ohmic contacts.…”