Muncy, Geissler, Olds & Lowe, P.C.
Self-aligned top contact for MRAM fabrication
Systems and methods for forming precise and self-aligned top metal contact for a Magnetoresistive random-access memory (MRAM) device include forming a magnetic tunnel junction (MTJ) in a common interlayer metal dielectric (IMD) layer with a logic element. A low dielectric constant (K) etch stop layer is selectively retained over an exposed top surface of the MTJ. Etching is selectively performed through a top IMD layer formed over the low K etch stop layer and the common IMD layer, based on a first chemistry which prevents etching through the low K etch stop layer. By switching chemistry to a second chemistry which precisely etches through the low K etch stop layer, an opening is created for forming a self-aligned top contact to the exposed top surface of the MTJ.
QUALCOMM INCORPORATED
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Xia Shiqun Yu Seung Hyuk
Li Gu Lu Kang