TY - GEN
T1 - 1.4 kV AlGaN/GaN HEMTs employing As+ ion implantation on SiO2 passivation layer
AU - Lim, Jiyong
AU - Choi, Young Hwan
AU - Cho, Kyu Heon
AU - Lee, Jihye
AU - Jo, William
AU - Han, Min Koo
PY - 2008
Y1 - 2008
N2 - We proposed As+ ion implantation on SiO2 passivation layer of AlGaN/GaN HEMTs to improve the forward and reverse electric characteristics of AlGaN/GaN HEMTs. SiO2 passivation layer which was applied in this work suppressed the electron hopping from gate to the surface states of gate-drain region so that the virtual gate formation was suppressed and the electric field concentration was terminated. As+ ions which were implanted on SiO2 passivation layer changed the depletion region curvature so that the electric field distribution became moderate. To verify that As+ ions exist as positively charged after ion implantation, we measured electric force microscopy (EFM) with EFM test sample. After ion implantation, 2DEG concentration was slightly increased due to the induced electrons in channel which is the counter-charge of positive ions in SiO2 layer generated by As+ ion implantation. Therefore, forward electric characteristics were slightly improved after ion implantation. Reverse characteristics were improved significantly after As+ ion implantation. The leakage current when VGD is -100 V and the breakdown voltage of the conventional device was 51.36 uA/mm and 523 V. The leakage current and the breakdown voltage under the same condition were improved to 38.82 uA/mm and 1380 V after As+ ion implantation under the condition of 80 keV energy and 1 × 1014 /cm2 dose. After annealing (400 °C, 10 min and N2 4 SLPM), most of positive charge was removed, which was observed by EFM measurement. The breakdown voltage was decreased and the leakage current was increased. These results showed that the improvement of electric characteristics of AlGaN/GaN HEMT is due to implanted As+ ions.
AB - We proposed As+ ion implantation on SiO2 passivation layer of AlGaN/GaN HEMTs to improve the forward and reverse electric characteristics of AlGaN/GaN HEMTs. SiO2 passivation layer which was applied in this work suppressed the electron hopping from gate to the surface states of gate-drain region so that the virtual gate formation was suppressed and the electric field concentration was terminated. As+ ions which were implanted on SiO2 passivation layer changed the depletion region curvature so that the electric field distribution became moderate. To verify that As+ ions exist as positively charged after ion implantation, we measured electric force microscopy (EFM) with EFM test sample. After ion implantation, 2DEG concentration was slightly increased due to the induced electrons in channel which is the counter-charge of positive ions in SiO2 layer generated by As+ ion implantation. Therefore, forward electric characteristics were slightly improved after ion implantation. Reverse characteristics were improved significantly after As+ ion implantation. The leakage current when VGD is -100 V and the breakdown voltage of the conventional device was 51.36 uA/mm and 523 V. The leakage current and the breakdown voltage under the same condition were improved to 38.82 uA/mm and 1380 V after As+ ion implantation under the condition of 80 keV energy and 1 × 1014 /cm2 dose. After annealing (400 °C, 10 min and N2 4 SLPM), most of positive charge was removed, which was observed by EFM measurement. The breakdown voltage was decreased and the leakage current was increased. These results showed that the improvement of electric characteristics of AlGaN/GaN HEMT is due to implanted As+ ions.
UR - http://www.scopus.com/inward/record.url?scp=52349098106&partnerID=8YFLogxK
U2 - 10.1109/PESC.2008.4591904
DO - 10.1109/PESC.2008.4591904
M3 - Conference contribution
AN - SCOPUS:52349098106
SN - 9781424416684
T3 - PESC Record - IEEE Annual Power Electronics Specialists Conference
SP - 88
EP - 91
BT - Proceedings - CIS Workshops 2007, 2007 International Conference on Computational Intelligence and Security Workshops, CISW 2007
T2 - PESC '08 - 39th IEEE Annual Power Electronics Specialists Conference
Y2 - 15 June 2008 through 19 June 2008
ER -