Hyun-sang Hwang

Resistance switching of Al doped ZnO for Non Volatile Memory applications

Introduction Since the first observation of the bi-stable resistance states in 1960s, a great amount of work has been done in an effort to understand the switching mechanism and to improve electrical properties for Resistance Random Access Memory (RRAM) applications. Consequently, numerous oxides materials such as Nb2O5 , TiO2 , NiO[1] , Al2O3 and ferroelectrics oxide have been reported for RRAM applications. However, high operating voltage and current, poor endurance, and low electrical uniformity made the resistance memory unfavorable. Recently, perovskite structure materials such as Pr1-xCaxMnO3 (PCMO)[2] and epitaxial Cr-doped SrTi(Zr)O3 [3-4] films have also shown welldeveloped resistance switching either by DC or AC modes. Considering perovskite oxides with more than three components system, it is difficult to apply these materials for conventional semiconductor manufacturing processes. In this point of view, binary oxides with good resistive switching behavior have advantages. In this paper, we have investigated the resistance switching characteristics of nonstoichiometric oxides such as ZrOx , STOx and Al doped ZnO (Al:ZnO) on the silicon for nonvolatile memory applications.

Triple high /spl kappa/ stacks (Al/sub 2/O/sub 3//HfO/sub 2//Al/sub 2/O/sub 3/) with high pressure (10 atm) H/sub 2/ and D/sub 2/ annealing for SONOS type flash memory device applications

In this article, we report on electrical and memory properties of triple high-/spl kappa/ stacks (Al/sub 2/O/sub 3//HfO/sub 2//Al/sub 2/O/sub 3/) with high pressure (10 atm) H/sub 2/ and D/sub 2/ annealing for SONOS type flash memory device applications. For 3 nm-thick Al/sub 2/O/sub 3//10 nm-thick HfO/sub 2//10 nm-thick Al/sub 2/O/sub 3/ (AHA) stack, memory window (M.W.) of 1.4 V at programming/erasing (P/E) condition of /spl plusmn/6 V/1-2 msec was obtained. In addition, high pressure D/sub 2/ annealed sample shows improved retention characteristics such as large memory window, and low slope per decade with retention time.