This document discloses non-volatile memory cells and methods of manufacturing the same. The etching liquid etches a gold or gold alloy layer formed on the surface of a substrate for a semiconductor device or a liquid crystal device evenly. The threads of the shaft have a first thread pitch in the reaction zone segments, and a second thread pitch in the dynamic plug segments. One or both mating sections may rotatably mount to its respective segment, thereby providing an articulated connection between the joined segments. The cylindrical permanent magnet is easy to orient magnetic character so that strong magnetic field can be provided at a low cost. Before the monitoring step, a substantially uniform conformal layer is formed on the substantially effective surface of the wafer, wherein the thickness of the conformal layer is controlled so that the apparent sizes of the particles and the defects possibly present on the wafer surface can be increased moderately.