ALEXANDRIA, Va., Dec. 31 -- United States Patent no. 12,512,329, issued on Dec. 30, was assigned to Tokyo Electron Ltd. (Tokyo).
"Multi level contact etch" was invented by Alec Dorfner (Miyagi, Japan) and Minjoon Park (Albany, N.Y.).
According to the abstract* released by the U.S. Patent & Trademark Office: "A method of processing a substrate that includes: forming a conformal etch stop layer (ESL) over a staircase pattern of the substrate, the staircase pattern including staircases, each of the staircases including a conductive surface; forming a dielectric layer over the ESL; planarizing a top surface of the dielectric layer; forming a patterned hardmask over the dielectric layer; and etching the dielectric layer selectively to the ESL ...