A comparison of close-cell, stripe-cell, and orthogonal-cell low voltage superjunction trench power MOSFETs for linear mode application

Abstract

Trade-offs between the On Resistance and Linear Mode performance have been compared for different Low Voltage superjunction cell structures, including stripe-cell, closed-cell & orthogonal-cell. The closed-cell has measured RSP of 4.4mΩ·mm2, which is 20% lower than that of the stripe-cell for the same die size and same pitch at the same package. Despite higher trans-conductance, the closed-cell linear mode performance is the same as that of the stripe-cell. The orthogonal-cell has the best linear mode performance, but has high Rds(on) due to current conduction path partially blocked by p-type superjunction column. The tested maximum load current is 38.4A at a drain voltage Vds of 10V and turn-on time of 10 mSec from the orthogonal-cell, which is the highest among the competitors' parts for a power 5×6 clip package. The Rds(on) for orthogonal-cell can be further improved by device optimization.