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

Abstract

Abstract:The specific on-resistance of non-uniform super-junction (SJ) trench metal-oxide semiconductor field-effect transistor (TMOS-FET) is superior to that of uniform SJ TMOSFET under the same breakdown voltage. For the desired blocking voltage with 100-V, the electric field varies exponentially with distance between the drain and the source regions. The idea with a linearly graded doping profile is proposed to achieve a much better electric field distribution in the drift region. The doping concentration linearly decreases in the vertical direction from the N drift region at the bottom to the channel one at the upper. The structure modeling and the characteristic analyses for doping density, potential distribution, and electric field are simulated by using of the SILVACO TCAD 2D device simulator, Atlas. As a result, the specific on-resistance of 0.66 mΩ · cm 2 at the class of 100 V and 100 A is successfully optimized in the non-uniform SJ TMOSFET, which has the better performance than the uniform SJ TMOSFET in the specific on-resistance.

Design of edge termination on non-uniform 100-V super-junction trench power MOSFET

“…2 a). The edge termination trench region has a width of 40 m and a depth of 10 m. The breakdown voltage for the edge termination was found to be 132 V which is identical to that of the non-uniform SJ TMOSFET [2]. This shows that the breakdown voltage is occurring in the cell region and is not limited by the edge termination.…”

“…The potential distribution in the uniform TMOSFET structure keeps constant [1], but the potential one in the nonuniform TMOSFET structure [5] increases linearly with distance in the drift region between the drain and source regions. The specific on-state resistance of non-uniform SJ TMOSFET is obtained 0.66 m･cm 2 from the structure [2], which is mainly composed of the channel resistance and the drift region resistance since the contributions from the source contact resistance, the source resistance, and the drain contact resistance are insignificantly negligible and can be ignored in this letter. The potential distributions obtained from the simulations at the edge termination for the breakdown voltage of 87 V and 132 V are demonstrated in Fig.…”

“…An interesting trade-off curve between the specific on-resistance and the breakdown voltage capability can be created by using the doping gradient in the drift region as a parametric variable. The reduction of the specific on-resistance for the non-uniform super-junction (SJ) trench metaloxide semiconductor field-effect transistor (TMOSFET) structure below the ideal specific on-resistance becomes larger with increasing breakdown voltage [1,2]. SJ TMOSFET power devices are well known for lower on-state resistance and gate charge.…”

Electrothermal Analysis for Super-Junction TMOSFET with Temperature Sensor

“…Super-junction (SJ) metal-oxide-semiconductor field-effect transistor (MOSFET) [1]- [2] power devices are well known for lower on-state resistance and gate charge. However, it is difficult to fabricate an exact balanced doping profile, and the impact of an imbalanced doping profile results in varying breakdown voltages (BVs).…”

“…An SJ TMOSFET, on the other hand, has P and N pillars, which are of equal widths, W P and W N , respectively, and is based on an SJ DMOSFET [1]- [2]. The doping concentrations of the P and N pillars in an SJ TMOSFET are denoted by N A and N D , respectively.…”