Patent ID: 6489882
Filing Date: 2002-12-03
Classification: H01L

Abstract:
A thin-film resistor formed on a semiconductor wafer, the thin-film resistor comprising:a dielectric layer deposited on the semiconductor wafer; an isolating layer formed in a predetermined area on the dielectric layer; a patterned resistance layer formed on the isolating layer; a buffering layer formed on the resistance layer, the buffering layer comprising two openings above two opposite ends of the resistance layer; a protective layer positioned on the buffering layer and comprising two openings above the two openings of the buffering layer; an insulating layer formed on the semiconductor wafer and covering the upper and side surfaces of the protective layer, the side surfaces of the buffering layer, the resistance layer, the isolating layer, and the surface of the dielectric layer, the insulating layer comprising two openings above the two openings of the protective layer; and two conductive layers positioned in the two openings of the buffering layer, the protective layer, and the insulating layer, the two conductive layers in contact with the two respective ends of the resistance layer, the two conductive layers being used as two electric terminals for connecting the two ends of the resistance layer; wherein the buffering layer is used to alleviate thermal stress exerted on the resistance layer from the protective layer, the protective layer is used to protect the resistance layer from plasma damage caused by a dry-etching process when forming the two openings of the insulating layer, and the isolating layer is used to isolate out-gassing produced by the dielectric layer so that the out-gassing does not affect the resistance of the thin-film resistor.