Abstract
New method to extract the amount of floating (FG) charge (Q FG ) apart from oxide trapped charge (Qox) generated by program and erase (P/E) cycles is proposed, for the first time. Q FG shift by P/E cycling shows asymmetry between programmed and erased states as follows; Q FG exhibits the peak at 100 cycles in programmed state, while Q FG monotonically reduces in erased state. Next, the midgap voltage (Vmid) shift of the cell caused by the generation of Q ox is also extracted by this method. Therefore, it enables to analyze the profiles of the hole and electron-trap separately across the oxide in detail. It is demonstrated that the hole-trap is mainly distributed near to Si surface and the centroid of electron-trap is located near to the middle of oxide. In addition, it is found that hole-trap near to Si has strong dependence on erase bias. © 2014 IEEE.