Novel lateral double-diffused MOSFET with folded silicon and high-permittivity dielectric breaking silicon limit

Abstract A novel folded-accumulation LDMOS (FALDMOS) employing high-permittivity (HK) material as the partial field dielectric (HK-FALDMOS) is proposed and investigated by simulation. The device features the high- k dielectric partially replacing conventional SiO 2 as the field oxide covering partial drift region and the gate electrode extending to the drain electrode. In the ON-state, the majority-carrier accumulation effect of HK-FALDMOS is more intense than that of FALDMOS, which is attributed to the larger capacitance of high- k film with the same dielectric thickness. Besides, a higher doping concentration in drift region I is obtained due to the electric field modulation effect resulting from the employed high- k film, which further reduces the specific on-resistance ( R on,sp ) of the drift region I. The breakdown voltage ( BV ) declines slightly with the increase of permittivity of high- k film. Simulation results show that the proposed HK-FALDMOS has best-in-class R on,sp - BV performance (9.9  mΩ mm 2 with BV of 44.9 V when the relative permittivity of high- k is 8), which breaks the silicon limit of LDMOS.