US Patent Issued to Kanto Kagaku on Sept. 8 for "Silicon nitride etching liquid composition" (Japanese Inventors)

ALEXANDRIA, Va., Sept. 8 -- United States Patent no. 12,729,340, issued on Sept. 8, was assigned to Kanto Kagaku K.K. (Tokyo).

"Silicon nitride etching liquid composition" was invented by Takuo Ohwada (Tokyo), Kohei Mochida (Tokyo) and Yuki Yoshida (Tokyo).

According to the abstract* released by the U.S. Patent & Trademark Office: "The present: invention addresses the problem of providing a silicon nitride etching liquid composition which is capable of selectively etching Si3N4 with a practical etching selectivity with respect to SiO2, while suppressing regrowth of SiO2, and which is also capable of suppressing pattern collapse of an SiO2 film in the production of a 3D nonvolatile memory cell. A silicon nitride etching liquid composition ...