Bilayer hardmask

Abstract

In one aspect, a method includes etching a magnetic field sensor element covered by a bilayer hardmask. In another aspect, a method includes depositing a silicon nitride on a magnetic field sensor element, depositing a silicon dioxide on the silicon nitride, forming the bilayer mask by etching the silicon dioxide and etching the magnetic field sensor element partially covered by the bilayer hardmask. The magnetic field sensor element includes one of a giant magnetoresistance (GMR) element, a tunneling magnetoresistance (TMR) element or a magnetic tunnel junction (MTJ). The bilayer mask includes the silicon dioxide and the silicon nitride. In a further aspect, a sensor includes a magnetic field sensor element that includes one of a GMR element, a TMR element or a MTJ. The sensor also includes a bilayer hardmask disposed on the magnetic field sensor element. The bilayer mask includes a silicon dioxide and a silicon nitride.

Dependencies are inferred from the claim text.