Method of forming a semiconductor device having a threshold switching device

It provides a method for forming a semiconductor device having a threshold switching device. The semiconductor device forming method includes forming a memory cell array on a semiconductor substrate. The memory cell array includes a first conductive lines and second conductive lines, the first and the memory cell, and containing memory cells between the second conductive lines are the data storage element and crossing the first conductive line It includes a threshold switching element and of the amorphous phase (amorphous phase). Maintaining said threshold switching elements in the amorphous state and proceeds to the switching element firing process for reducing the threshold voltage variation of the threshold switching device.