SELF ALIGNED SHALLOW TRENCH ISOLATION WITH IMPROVED COUPLING COEFFICIENT IN FLOATING GATE DEVICES

摘要

The present invention provides a method for manufacturing a floating gate type semiconductor device on a substrate having a surface (2), and a device thus manufactured.The method comprises: - forming, on the substrate surface, a stack comprising an insulating film (4), a first layer of floating gate material (6) and a layer of sacrificial material (8), - forming at least one isolation zone (18) through the stack and into the substrate (2), the first layer of floating gate material (6) thereby having a top surface and side walls (26), - removing the sacrificial material (8), thus leaving a cavity (20) defined by the isolation zones (18) and the top surface of the first layer of floating gate material (6), and filling the cavity (20) with a second layer of floating gate material (22), the first layer of floating gate material (6) and the second layer of floating gate material (22) thus forming together a floating-gate (24).