Novel high-voltage power lateral MOSFET with adaptive buried electrodes

A new high-voltage and low-specific on-resistance (R_on,sp) adaptive buried electrode (ABE) silicon-on-insulator (SOI) power lateral MOSFET and its analytical model of the electric fields are proposed. The MOSFET features are that the electrodes are buried in the buried oxide (BOX) layer, the negative drain voltage V_d is divided into many partial voltages and output to the electrodes in the buried oxide layer, the potentials on the electrodes change linearly from the drain to the source. Because the interface silicon layer potentials are lower than the neighboring electrode potentials, the electronic potential wells are formed above the electrode regions, and the hole potential wells are formed in the spacings of two neighbouring electrode regions. The interface hole concentration is much higher than the electron concentration through designing the buried layer electrode potentials. Based on the interface charge enhanced dielectric layer field theory, the electric field strength in the buried layer is enhanced. The vertical electric field E_I and the breakdown voltage (BV) of ABE SOI are 545 V/μm and -587 V in 50 μm long drift region and 1 μm thick dielectric layer, and a low R_on,sp is obtained. Furthermore, the structure also alleviates the self-heating effect (SHE). The analytical model matches well with the simulation result.