Title :
Improvement of Interpoly Dielectric Characteristics by Plasma Nitridation and Oxidation for Future nand Flash Memory
Author :
Ho, Ching Yuan ; Lien, Chenhsin ; Sakamoto, Y. ; Yang, Ru Jye ; Fijita, Hiro ; Liu, C.H. ; Lin, Y.M. ; Pittikoun, S. ; Aritome, S.
Author_Institution :
Memory Technol. Center, Powerchip Semicond. Corp., Hsinchu
Abstract :
In this letter, plasma nitridation and oxidation on interpoly dielectric (IPD; SiO2-SiN-SiO2 ) for cell programming speed and reliabilities are investigated. Nitrided top oxide with N2 plasma shows excellent physical and electrical properties in terms of edge profile on IPD and fast programming voltage. However, plasma nitridation on a floating gate suffers from data retention problems that result from nitridelike residue along the word line. A method to densify and reoxidize bottom oxide with O2 plasma oxidation is proposed for leakage path inhibition and data retention improvement.
Keywords :
dielectric materials; dielectric thin films; flash memories; logic gates; nitridation; oxidation; plasma materials processing; silicon compounds; surface treatment; IPD; N2 plasma; NAND flash memory; SiO2-SiN-SiO2; cell programming speed; data retention; edge profile; electrical property; fast programming voltage; floating gate; interpoly dielectric characteristics; leakage path inhibition; nitrided top oxide; oxidation; plasma nitridation; reliability; reoxidation; Dielectrics; Nonvolatile memory; Oxidation; Plasma applications; Plasma density; Plasma devices; Plasma properties; Semiconductor films; Silicon; Voltage; Data retention; interpoly dielectric (IPD); plasma nitridation; programming speed;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2008.2004972
