a thin film resistor is contained between two metal interconnect layers of an integrated circuit . contact may be made to the resistor through vias from the metal layer above the resistor to both the thin film resistor and the underlying metal layer simultaneously . the resistor may include portions of a hard mask under the vias to protect the resistor material during the via etch . this design provides increased flexibility in fabricating the resistor since processes , materials , and chemicals do not have to satisfy the conditions of both the resistor and the rest of the integrated circuit simultaneously .