Design of 100-V Super-Junction Trench Power MOSFET with Low On-Resistance

Abstract

Power metal-oxide semiconductor field-effect transistor (MOSFET) devices are widely used in power electronics applications, such as brushless direct current motors and power modules. For a conventional power MOSFET device such as trench double-diffused MOSFET (TDMOS), there is a tradeoff relationship between specific on-state resistance and breakdown voltage. To overcome the tradeoff relationship, a super-junction (SJ) trench MOSFET (TMOSFET) structure is studied and designed in this letter. The processing conditions are proposed, and studies on the unit cell are performed for optimal design. The structure modeling and the characteristic analyses for doping density, potential distribution, electric field, width, and depth of trench in an SJ TMOSFET are performed and simulated by using of the SILVACO TCAD 2D device simulator, Atlas. As a result, the specific on-state resistance of 1.2 mΩ-cm 2 at the class of 100 V and 100 A is successfully optimized in the SJ TMOSFET, which has the better performance than TDMOS in design parameters.

Design of non-uniform 100-V super-junction trench power MOSFET with low on-resistance

“…The components of the on-resistance for the power non-uniform TMOS-FET [2] are similar as those described for the power uniform one [3]. However, the drift region resistance in the power non-uniform TMOSFET structure is much lower than that for the power uniform one due to the higher doping concentration in the drift region and an improved electric field distribution.…”

“…The potential distribution in log scale for the uniform TMOSFET structure [3] keeps constant, but the potential one in the non-uniform TMOSFET structure decreases exponentially with distance in the P pillar and increases in the N pillar between the drain and source regions. The relationship between the doping concentration of D N (y) and the distance of y from the top of unit cell toward substrate can be written as…”

“…However, the drift region resistance in the power non-uniform TMOSFET structure is much lower than that for the power uniform one due to the higher doping concentration in the drift region and an improved electric field distribution. The total on-resistance for the power non-uniform TMOSFET structure is computed by combining the seven resistances [3] in the current path between the source and the drain electrodes. The contributions from the source contact resistance, the source resistance, and the drain contact resistance are insignificantly negligible and can be ignored in this paper.…”

Simulation and Fabrication Studies of Semi-superjunction Trench Power MOSFETs by RSO Process with Silicon Nitride Layer

“…To overcome the "silicon limit" of a discrete power device, Manuscript [4] and superjunction (SJ) [5]- [10] concepts are preferred over a vertical double diffused MOSFET (VDMOSFET). These devices have such inherent characteristics as a low specific on-resistance (R ON,SPEC ), a high switch speed, and a high current derivability.…”

Fabrication of Superjunction Trench Gate Power MOSFETs Using BSG-Doped Deep Trench of p-Pillar

“…The power MOSFETs used in power converters operate as switching devices, and their associated dissipation loss consists of conduction loss while the power MOSFET is in an on state and switching loss when it turns on and off. To reduce the dissipation loss of a power MOSFET, a minimization of the on-resistance per unit area (R ON •A) and gate-to-drain charge is normalized to the on-resistance (R ON •Q GD ) [1], [2]. However, for a conventional power MOSFET, there is a fundamental tradeoff between the breakdown voltage and specific R ON , and it is not thought to be possible to obtain an R ON •A value that exceeds the silicon limit.…”