THIN FILM RESISTOR HEAD STRUCTURE AND METHOD FOR REDUCING HEAD RESISTIVITY VARIANCE

摘要

A method of making integrated circuit thin film resistor includes forming a first dielectric layer ( 18 B) over a substrate and providing a structure to reduce variation of head resistivity thereof by forming a dummy fill layer ( 9 A) on the first dielectric layer, and forming a second dielectric layer ( 18 D) over the first dummy fill layer. A thin film resistor ( 2 ) is formed on the second dielectric layer ( 18 D). A first inter-level dielectric layer ( 21 A) is formed on the thin film resistor and the second dielectric layer. A first metal layer ( 22 A) is formed on the first inter-level dielectric layer and electrically contacts a portion of the thin film resistor. Preferably, the first dummy fill layer is formed as a repetitive pattern of sections such that the repetitive pattern is symmetrically aligned with respect to multiple edges of the thin-film resistor ( 2 ). Preferably, the first dummy fill layer is formed so as to extend sufficiently far beyond ends of the thin-film resistor to ensure only a negligible amount of systematic resistance error due to misalignment.