ALEXANDRIA, Va., Feb. 17 -- United States Patent no. 12,555,643, issued on Feb. 17, was assigned to Sandisk Technologies Inc. (Milpitas, Calif.).
"Dummy memory hole defect detection" was invented by Yusuke Ikawa (Yokohama, Japan), Xiaolong Hu (Yokkaichi, Japan) and Kei Samura (Yokohama, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "Technology for detection of defects in dummy memory holes in a 3D NAND memory structure. Dummy bit lines connected to dummy memory holes are used to detect defects associated with the dummy memory holes. A system may perform a stress test in which a stress voltage is applied to one or more word lines while another voltage (e.g., 0V) is applied to the dummy bit lines. The sy...