Superjunction Trench Structure Charge Balance

The patent applies local quality by differentiating the doping structure along the trench depth. The first doped region (n-type) extends from the surface to a first depth, while the second doped region (p-type) extends from the surface to a second depth that is less than the first depth. This creates a depth-dependent doping profile where the n-type region penetrates deeper than the p-type region, compensating for charge imbalances that occur in conventional uniform doping structures. This local variation in doping depth optimizes charge balance in specific trench locations while maintaining overall device reliability and manufacturing yields.

The patent employs parameter changes by establishing specific depth parameters for the doped regions. The first doped region extends to a first depth while the second doped region extends to a second depth that is explicitly defined as less than the first depth. This parameter differentiation creates a controlled asymmetry in the doping profile that improves breakdown voltage without requiring uniformly deep trenches throughout the device. The specific depth parameters are optimized to achieve charge balance while being tolerant of manufacturing variations in trench formation processes.

The patent applies segmentation by dividing the doped regions into distinct segments with different properties. The first doped region (n-type) and second doped region (p-type) are segmented both by conductivity type and by depth extent. The first doped region extends deeper than the second doped region, creating spatially segmented doping zones. This segmentation allows each region to be optimized for its specific function while maintaining a relatively simple manufacturing process that uses standard ion implantation or diffusion techniques with different depth controls for each region.