Image sensors having high density subpixels therein with enhanced pixel separation structures

Abstract

An image sensor is provided, and the image sensor includes: a substrate having first and second surfaces spaced apart from each other in a vertical direction; a first color unit pixel including a first subpixel to a fourth subpixel arranged in a 2×2 matrix; a second color unit pixel including four subpixels arranged in a 2×2 matrix; a first pixel isolation trench separating the first color unit pixel and the second color unit pixel; a second pixel isolation trench separating the first subpixel and the second subpixel of the first color unit pixel; a third pixel isolation trench on a point of intersection of the first to fourth subpixels of the first color unit pixel. The first color unit pixel detects first color light. The second color unit pixel detects second color light. The image sensor is configured to receive the first color light on the second surface. The second pixel isolation trench extends from the first surface to the second surface. The third pixel isolation trench extends from the second surface to the first surface.