US 11,990,257 B2
Thin film resistor (TFR) formed in an integrated circuit device using wet etching of a dielectric cap
Paul Fest, Chandler, AZ (US)
Assigned to Microchip Technology Incorporated, Chandler, AZ (US)
Filed by Microchip Technology Incorporated, Chandler, AZ (US)
Filed on Oct. 15, 2020, as Appl. No. 17/071,356.
Claims priority of provisional application 62/982,107, filed on Feb. 27, 2020.
Prior Publication US 2021/0272726 A1, Sep. 2, 2021
Int. Cl. H01C 17/30 (2006.01); H01C 7/00 (2006.01); H01C 17/00 (2006.01); H01L 27/06 (2006.01); H01L 49/02 (2006.01)
CPC H01C 17/30 (2013.01) [H01C 7/006 (2013.01); H01C 17/006 (2013.01); H01L 27/0629 (2013.01); H01L 28/24 (2013.01); Y10T 29/49082 (2015.01)] 13 Claims
OG exemplary drawing
 
1. A method of forming an integrated thin film resistor (TFR) in a semiconductor integrated circuit device, the method comprising:
forming an integrated circuit (IC) structure including a plurality of IC elements and a plurality of conductive IC element contacts connected to the plurality of IC elements;
forming a TFR film layer over the formed IC structure;
forming a TFR dielectric layer over the TFR film layer;
performing a wet etch to remove selected portions of the TFR dielectric layer to thereby define a TFR dielectric cap over the TFR film layer, wherein the wet etch stops at the TFR film layer, and wherein the wet etch defines sloped lateral edges of the TFR dielectric cap;
after the wet etch, performing a TFR etch to remove selected portions of the TFR film layer to thereby define a TFR element;
performing a TFR contact etch to form at least one TFR contact opening in the TFR dielectric cap over the TFR element; and
forming a metal layer extending over the conductive IC element contacts and over the TFR dielectric cap, and extending into the at least one TFR contact opening and in contact with the TFR element; and
at some time after forming the TFR film layer and before forming the metal layer, annealing the TFR film layer or the TFR element.