Formation and Nonvolatile Memory Application of Ge Nanocrystals by Using Internal Competition Reaction of Si(1.33)Ge(0.67)O(2) and Si(2.67)Ge(1.33)N(2) Layers

Abstract

In this study, the authors proposed a formation mechanism of Ge nanocrystals (NCs) embedded in the dielectric by using Si(1.33)Ge(0.67)O(2) and Si(2.67)Ge(1.33)N(2) films for nonvolatile memory (NVM) application. Because of internal competition reaction, this formation process reduced the thermal budget and eliminated the use of high-pressure H(2) treatment or steam process. The metal/oxide/insulator/oxide/silicon capacitor structure with NCs was also studied, and exhibited hysteresis characteristics after electrical operation. Transmission electron microscopy clearly shows the shape and density of NCs in the dielectric. In addition, the obvious memory window can be used to define "1" and "0" states at low-voltage program operation. Furthermore, good endurance and retention characteristics are exhibited for the Ge NCs embedded in SiN(x) structure. Besides, this technology is suitable for the current NVM fabrication and low-power device application.