Studies of metal-ferroelectric-GaN structures

A GaN-based metal-insulator-semiconductor (MIS) structure has been fabricat ed by using ferroelectric Pb(Zr0.53Ti0.47)O-3 instead of conventional oxide s as insulator gate. Because of the polarization field provided by ferroele ctric and the high dielectric constant of ferroelectric insulator, the capa citance-voltage characteristics of GaN-based metal-ferroelectric-semiconduc tor (MFS) structures are markedly improved compared to those of other previ ously studied GaN MIS structures. The GaN active layer in MFS structures ca n reach inversion just under the bias of smaller than 5 V, which is the gen erally applied voltage used in semiconductor-based integrated circuits. The surface carrier concentration of the GaN layer in the MFS structure is dec reased by one order compared with the background carrier concentration. The GaN MFS structures look promising for the practical application of GaN-bas ed field effect transistors. (C) 1999 American Institute of Physics. [S0003 -6951(99)00342-3].