Metal line formation method of NAND flash memory, involves etching nitride film exposed through trench, to expose drain contact plug, and forming metal line, to bury trench

摘要

An interlayer insulation film (124) formed on a nitride film (123) is patterned so that the nitride film formed on protruded portion of a drain contact plug (122) is exposed forming a trench. The nitride film exposed through the trench is etched, to expose the drain contact plug. The metal line is formed, to bury the trench.