BLC Pixel Optical Blocking Structure for Light Leakage Suppression

The patent applies composite materials by using multiple alternating layers of materials with different refractive indices (e.g., silicon nitride and silicon oxide) to create an optical blocking structure. This composite structure enhances light blocking capability through constructive interference of reflected light waves at each interface, thereby suppressing light leakage and improving measurement precision in black level correction pixels.

The patent segments the light blocking function into multiple thin layers rather than using a single thick layer. Each layer is optimized for specific optical properties, and the alternating refractive indices create multiple reflection interfaces. This segmentation allows precise control over light blocking across different wavelengths while maintaining manufacturability through standard deposition processes.

The patent uses composite materials with alternating high and low refractive index layers to achieve superior light blocking performance. The specific combination of materials (such as silicon nitride and silicon oxide) and their alternating structure creates optical interference that enhances blocking capability, improving reliability of black level correction while remaining compatible with standard semiconductor manufacturing processes.

The patent optimizes the thickness of each layer in the alternating structure to specific values that maximize light blocking through constructive interference. By carefully controlling the optical thickness parameters of each layer (typically quarter-wave thicknesses), the structure achieves enhanced light blocking performance across the relevant wavelength range, improving black level correction accuracy.