Nonvolatile Floating Gate Memory Devices Containing AgInSbTe-SiO2 Nanocomposite Thin Film Prepared by Sputtering Method

Abstract

AbstractAgInSbTe (AIST)-SiO2 nanocomposite layer prepared by a one-step sputtering process utilizing target-attachment method was implanted in the nonvolatile floating gate memory (NFGM) devices. Device sample subjected to post annealing at 400°C for 2 min in atmospheric ambient exhibited a significant hysteresis memory window (ΔVFB) shift = 5.91V and charge density = 5.22×12 cm-2 after ±8V voltage sweep. During the retention time test, a ΔVFB shift about 3.50 V and charge loss about 28.4% were observed in the sample after a ±5V voltage stress for 104 sec. Cross-sectional TEM revealed that the nanocomposite layer contains the crystalline AIST nanoparticles with the sizes about 5 to 7 nm embedded in SiO2 matrix. XPS analysis indicated that annealing induces the reduction of antimony oxides to form metallic Sb nanocrystals and suppresses the oxygen defects and charge loss in nanocomposite layer. Analytical results illustrated that the utilization of AIST-SiO2 nanocomposite layer may simplify the preparation of NFGM device with satisfactory electrical properties, implying a promising feasibility of such a nanocomposite layer to NFGM devices.