Lam Research Assigned Patent

Lam Research Corporation, Fremont, CA, has been assigned a patent (10,741,407) developed by Dole, Nikhil, Union City, CA, Yanagawa, Takumi, and Song, Anqi, Fremont, CA, for a “reduction of sidewall notching for high aspect ratio 3D NAND etch.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: ”Methods and apparatus for etching a high aspect ratio feature in a stack on a substrate are provided. The feature may be formed in the process of forming a 3D NAND device. Typically, the stack includes alternating layers of material such as silicon oxide and silicon nitride or silicon oxide and polysilicon. WF.sub.6 is provided in the etch chemistry, which substantially reduces or eliminates problematic sidewall notching. Advantageously, this improvement in sidewall notching does not introduce other tradeoffs such as increased bowing, decreased selectivity, increased capping, or decreased etch rate.”

The patent application was filed on October 19, 2018 (16/165,471).