FinFET Local Buried Oxide for Leakage and Stress Control

The patent applies local quality by implementing a non-planar fin structure in specific regions rather than using a uniform planar structure throughout. The fin structure creates localized stress fields in the channel region that enhance carrier mobility, while maintaining the thin body thickness for good short channel control. This resolves the contradiction by providing different structural characteristics in different locations: planar structure for overall device control and non-planar fin structure for localized mobility enhancement.

The patent transitions from a two-dimensional planar structure to a three-dimensional non-planar fin structure. This dimensional change allows the thin silicon body to extend vertically, creating a larger effective channel width without increasing the planar footprint. The fin structure provides additional pathways for current flow, reducing source/drain resistance while maintaining the thin body thickness that suppresses junction leakage.

The patent introduces dynamic structural features through the non-planar fin configuration, which creates inherent mechanical stability through its three-dimensional geometry. The fin structure's vertical extensions provide rigidity and stress distribution that planar structures cannot achieve, while still being compatible with standard semiconductor fabrication processes. This allows the device to maintain manufacturability while gaining the mechanical stability needed for effective stress induction.