Trench MOSFET Layout With Bridge Trenches for Higher Channel Density

The shield gate structure is divided into multiple independent gate trenches arranged in a specific pattern, allowing each gate trench to function separately while collectively providing the shielding effect. This segmentation enables better space utilization and increased cell density compared to a single large shield gate structure.

The patent transitions from a planar shield gate layout to a three-dimensional trench structure with multiple levels and orientations. The gate trenches are arranged in a pattern that utilizes vertical and lateral dimensions effectively, increasing the functional gate area without proportionally increasing the planar footprint, thus improving cell density.

The deep trench structure is segmented into multiple shallower gate trenches distributed throughout the drift zone. Each trench creates a localized depletion region, and the collective effect of multiple trenches achieves the desired overall depletion of the drift zone. This segmentation simplifies the manufacturing process compared to forming a single extremely deep trench while maintaining the electrical performance benefits.

Instead of creating one uniform deep trench structure, the patent implements multiple trenches with locally optimized dimensions and spacing. Each trench is positioned to create the appropriate electric field in its local region, allowing the drift zone to be depleted through the combined effect of multiple localized fields rather than requiring a single complex deep structure.