The invention provides a lateral power device with a mixed
conduction mode and a preparation method thereof, comprising a P-type substrate, a
buried oxide layer, an N-type drift region, a P-type base region, an N-type buffer region, an N-type source region, a P-type
Contact region, P-type collector region, emitter, collector,
gate dielectric layer, gate
electrode, N-type drift region surface has N-type strips and P-type strips, N-type strips and P-type strips are perpendicular to the device drift region surface The channel length direction is arranged alternately, and there is a
dielectric buried layer in the drift region under the N-type strip and the P-type strip; there is a
dielectric groove structure between the N-type strip, the P-type strip, the
dielectric buried layer and the N-type
buffer zone; the N-type strip and the P-type strip. The concentration of the P-type strip is greater than the concentration of the N-type drift region; the invention realizes the mixed conduction of the surface SJ-
LDMOS and LIGBT, and can obtain lower conduction
voltage drop, higher withstand
voltage, faster switching speed, and more Low turn-off loss, and eliminate the
snapback effect, greatly improving device performance.