Physical simulation and modeling of low ohmic contact resistivity for gallium nitride high electron mobility transistor (GaN HEMT) device

• Published in: AIP Conference Proceedings
• Main Author: Siong T.K.; Mohamed M.F.P.; Baharin M.S.N.S.; Rahim A.F.A.
• Format: Conference paper
• Language: English
• Published: American Institute of Physics Inc. 2023
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85178037643&doi=10.1063%2f5.0122499&partnerID=40&md5=c0c240ca4a08b244aee3e68dc829ab49

Recent research has led to Gallium Nitride (GaN) as promising material, enhancing properties like higher operational temperature, smaller dimension, faster operation, and efficient performance. As metal contact on the semiconductor is essential to provide the HEMT's device external connection, no significant work has been found that focuses on physical modelling to analyze the contact resistance and implementation methods to reduce the contact resistivity. Hence, this work focuses on physical-based modelling using Silvaco ATLAS TCAD to model and further investigate the effect of the parameters and structures of GaN's on its Ohmic contact resistance. One of the crucial physical model which is Universal Schottky Tunneling (UST), was chosen to calibrate the thermionic (and field emission) between the metal contact and effective mass for various heavily doped n++ layer under the metal contact to obtain the best optimization for the low ohmic contact resistivity. The result revealed the reduction in contact resistivity by 100 % for doping layer thickness 18 nm and above with heavy doping n++ layer≥1E+19 cm-3. This work would be beneficial to reduce the cost of experimental trials by narrowing the optimization process windows to achieve low contact resistivity. © 2023 Author(s).