Development of large-area BaTi0/sub 3/ ceramics with optimized depletion regions as dielectrics for planar power electronics

High-voltage (500 V) barium titanate (BaTiO/sub 3/) ceramics are under development as compact high-permittivity dielectrics for planar structures in integrated power-electronic converters. Dielectric requirements include a high permittivity for meeting the dimensional constraints in converters, a high power-handling capability, low loss, and flat permittivity and tan/spl delta/ frequency responses up to 1 MHz. Dopant materials examined here focused on fine powders of Al/sub 2/0/sub 3/ and Al added during the sintering process. Best results were obtained by diffusion of externally-placed Al during the sintering cycle, with BaTiO/sub 3/ permittivities /spl epsiv//sub r//spl sim/1000, and loss tangents tan/spl delta/