Title :
High work-function metal gate and high-κ dielectrics for charge trap flash memory device applications
Author :
Jeon, Sanghun ; Han, Jeong Hee ; Lee, Jung Hoon ; Choi, Sangmoo ; Hwang, Hyunsang ; Kim, Chungwoo
Author_Institution :
Devices Lab., Samsung Adv. Inst. of Technol., Kyungki-Do, South Korea
Abstract :
We report the impact of high work-function (ΦM) metal gate and high-κ dielectrics on memory properties of NAND-type charge trap Flash (CTF) memory devices. In this paper, theoretical and experimental studies show that high ΦM gate and high permittivity (high-κ) dielectrics play a key role in eliminating electron back tunneling though the blocking dielectric during the erase operation. Techniques to improve erase efficiency of CTF memory devices with a fixed metal gate by employing various chemicals and structures are introduced and those mechanisms are discussed. Though process optimization of high ΦM gate and high-κ materials, enhanced CTF device characteristics such as high speed, large memory window, and good reliability characteristics of the CTF devices are obtained.
Keywords :
NAND circuits; alumina; dielectric materials; flash memories; integrated circuit reliability; optimisation; permittivity; silicon compounds; work function; Al2O3-SiN-SiO2-Si; CTF memory devices; NAND-type charge trap flash memory devices; SONOS devices; Si-SiO2-SiN-SiO2-Si; erase efficiency; high permittivity dielectrics; high work-function metal gate; high-k dielectrics; memory properties; process optimization; Annealing; CMOS technology; Chemicals; Dielectric devices; Dielectric materials; Electron traps; Flash memory; Materials science and technology; Permittivity; Tunneling; Charge trap Flash (CTF) memory; NAND; electron back tunneling (ETB); erase; high-; metal gate; work function;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2005.859691