A thick SOI LIGBT structure with a combination of uniform and variation in lateral doping profiles (UVLD) on partial membrane(UVLD PM LIGBT) is proposed.The silicon substrate under the drift region is selectively etched to remove the charge beneath the buried oxide so that the potential lines can release below the membrane,resulting in an enhanced breakdown voltage.Moreover,the thick SOI LIGBT with the advantage of a large current flowing and a thermal diffusing area achieves a strong current carrying capability and a low junction temperature.The current carrying capability(K_(Anode) = 6 V,V_(Gate) = 15 V) increases by 16%and the maximal junction temperature(1 mW/μm) decreases by 30 K in comparison with that of a conventional thin SOI structure. A thick SOI LIGBT structure with a combination of uniform and variation in lateral doping profiles (UVLD PM LIGBT) is proposed. The silicon substrate under the drift region is selectively etched to remove the charge beneath the buried oxide so that the potential lines can release below the membrane, resulting in an enhanced breakdown voltage. Moreover, the thick SOI LIGBT with the advantage of a large current flowing and a thermal diffusing area achieves a strong current carrying capability and a low junction temperature. The current carrying (K_ Anode = 6 V, V Gate = 15 V) increases by 16% and the maximal junction temperature (1 mW / μm) decreases by 30 K in comparison with that of a conventional thin SOI structure.