Improvement of memory characteristics by employing a charge trapping layer with combining bent and flat energy bands*

Abstract

Designed Zr x Si1−x O2 films with combining bent and flat energy bands are employed as a charge trapping layer for memory capacitors. Compared to a single bent energy band, the bandgap structure with combining bent and flat energy bands exhibits larger memory window, faster program/erase speed, lower charge loss even at 200 °C for 104 s, and wider temperature insensitive regions. The tunneling thickness together with electron recaptured efficiency in the trapping layer, and the balance of two competing electron loss mechanisms in the bent and flat energy band regions collectively contribute to the improved memory characteristics. Therefore, the proposed Zr x Si1−x O2 with combining bent and flat energy bands should be a promising candidate for future nonvolatile memory applications, taking into consideration of the trade-off between the operation speed and retention characteristics.