Patent ID: 11944020
Assignee: CROSSBAR, INC.
Field: nan (nan)
Classification: CPC H | IPC H

Claim 0:
1. A method, comprising:
forming layers of a volatile two-terminal selector device, the layers of the volatile two-terminal selector device including a top electrode layer, a bottom electrode layer, and an active region disposed between the top electrode layer and the bottom electrode layer, the top electrode layer comprising a material selected from a group consisting of: silver, a silver compound, a silver alloy, aluminum, an aluminum compound, and an aluminum alloy;
forming a buffer layer overlaying and in contact with the top electrode layer of the layers of the volatile two-terminal selector device, wherein the buffer layer comprises TiN or TaN;
forming an etch stop layer overlaying and in contact with the buffer layer, the etch stop layer comprising a material selected from a second group consisting of: aluminum, an aluminum compound, and an aluminum alloy;
forming a top cap layer overlaying and in contact with the etch stop layer, wherein the top cap layer comprises an electrically conductive material that is selected from a third group consisting of: TiN and TaN;
etching with a first etch procedure of a two-step etch at least a portion of the top cap layer using a chemical etchant selected from a fourth group consisting of: boron trichloride (BCl3), chlorine (Cl), and a compound comprising Cl, Cl2, or BCl3, and terminating the first etch procedure when the etch stop layer is exposed, wherein the top electrode layer is substantially free of chlorine impurities from the chemical etchant; and
etching with a second etch procedure of the two-step etch a portion of the etch stop layer exposed by the first etch procedure and respective portions of the buffer layer, the top electrode layer, the active region and the bottom electrode layer underlying the portion of the etch stop layer exposed by the first etch procedure, wherein the second etch procedure comprises a physical etch procedure.