Top electrode etch in a magnetoresistive device and devices manufactured using same

摘要

A two-step etching process is used to form the top electrode for a magnetoresistive device. The etching chemistries are different for each of the two etching steps. The first chemistry used to etch the top portion of the electrode is more selective with respect to the conductive material of the top electrode, thereby reducing unwanted erosion of the photoresist and hard mask layers. The second chemistry is less corrosive than the first chemistry and does not damage the layers underlying the top electrode, such as those included in the magnetic tunnel junction.

主权项

1. A method of manufacturing a magnetoresistive-based device, comprising:
forming a patterned layer of photoresist over an electrically conductive layer; etching, using a first etching chemistry, a first portion of the electrically conductive layer not covered by the patterned layer of photoresist, wherein the first etching chemistry is a selective etching chemistry that favors removal of material in the electrically conductive layer over material in the patterned layer of photoresist; after etching the first portion, etching, using a second etching chemistry, a second portion of the electrically conductive layer not covered by the patterned layer of photoresist, wherein the first etching chemistry is more selective with respect to the electrically conductive layer than the second etching chemistry; and after etching the second portion, stripping the patterned layer of photoresist.