Effect of High Temperature Forming Gas Annealing on Electrical Properties of 4H-SiC Lateral MOSFETs with Lanthanum Silicate and ALD SiO2 Gate Dielectric
We investigated the impact of an initial lanthanum oxide (La2O3) thickness and forming gas annealing (FGA) conditions on the MOSFET performance. The FGA has been shown to dramatically improve the threshold voltage (VT) stability of 4H-SiC MOSFETs. The FGA process leads to low VT shift and high field effect mobility due to reduction of the interface states density as well as traps by passivating the dangling bonds and active traps in the Lanthanum Silicate dielectrics. By optimizing the La2O3 interfacial layer thickness and FGA condition, SiC MOSFETs with high threshold voltage and high mobility while maintaining minimal VT shift are realized.
Robert Stahlbush, Philip Neudeck, Anup Bhalla, Robert P. Devaty, Michael Dudley and Aivars Lelis
M. S. Kang et al., "Effect of High Temperature Forming Gas Annealing on Electrical Properties of 4H-SiC Lateral MOSFETs with Lanthanum Silicate and ALD SiO2 Gate Dielectric", Materials Science Forum, Vol. 924, pp. 482-485, 2018