1.  Technical Field
The disclosure relates in general to a semiconductor element and an operating method thereof, and more particularly to a semiconductor memory and an operating method thereof. 
2.  Description of the Related Art
With the development of semiconductor technology, varied semiconductor elements are invented.  Those semiconductor elements are widely used in electric devices.  Semiconductor memory can store digital data, so that the semiconductor memory plays an important role in varies electric devices. 
Semiconductor memory stores data by a binary system.  Each unit of the semiconductor memory is called as a memory cell.  The memory cell can be selected to be controlled as two kinds of electric characteristics.  According to the two kinds of electric characteristics, “0” and “1” can be defined for saving a binary data.