Title :
Investigation of Thermal Stability of High-kappa Interpoly Dielectrics in TaN Metal Floating Gate Memory Structures
Author :
Jayanti, Srikant ; Yang, Xiangyu ; Misra, Veena
Author_Institution :
Dept. of Electr. & Comput. Eng., North Carolina State Univ., Raleigh, NC, USA
Abstract :
Metal as floating gate (FG) in combination with high-k interpoly dielectrics (IPD) is seen as a possible solution to continue the scaling of NAND Flash technology node beyond 25nm. We have investigated the thermal stability of TaN metal as FG in combination with Hf based high-k IPD stacks. IPD leakage is found to worsen with high temperature anneal and causing degraded memory behavior. Comparative leakage study of high-k dielectrics on metal and Si substrates were performed through metal-insulator-metal (MIM) and metal-insulator semiconductor (MIS) structures. The leakage degradation was observed to be higher in case of MIM, which was attributed to the higher degree of dielectric crystallization on metal. The thermal stability of the high-k IPD on TaN metal FG memory structure has to be improved for potential application in future NAND flash memory.
Keywords :
MIM structures; MIS structures; NAND circuits; flash memories; logic gates; tantalum compounds; thermal stability; IPD leakage; MIM structure; MIS structure; NAND flash memory; Si; TaN; dielectric crystallization; high-k interpoly dielectrics; metal floating gate memory structures; metal-insulator-metal structure; metal-insulator-semiconductor structure; thermal stability; Annealing; Dielectrics; High K dielectric materials; Metals; Silicon; Substrates; Thermal stability;
Conference_Titel :
Memory Workshop (IMW), 2011 3rd IEEE International
Conference_Location :
Monterey, CA
Print_ISBN :
978-1-4577-0225-9
Electronic_ISBN :
978-1-4577-0224-2
DOI :
10.1109/IMW.2011.5873183
