Title :
Trap Profiling in Nitride Storage Layer in 3-D NAND Flash Memory Using Retention Characteristics and AC-
Method
Author :
Min-Kyu Jeong ; Ho-Jung Kang ; Sung-Min Joe ; Sung-Kye Park ; Byung-Gook Park ; Jong-Ho Lee
Author_Institution :
R&D Div., SK Hynix Inc., Icheon, South Korea
Abstract :
The trap density (Nt) in nitride storage layer of 3-D NAND flash memory cells with tube-type channel structure is extracted. To extract Nt profile in the nitride layer, retention characteristics, and ac-transconductance (gm) method are used, and equations are derived in cylindrical coordinate. The Nt profile at E - ET smaller than 1 eV is extracted using retention characteristics of the cells measured at high temperature. The peak value of extracted Nt is ~1 × 1019 cm-3 eV-1 at a EC - ET of 0.93 eV. AC-gm method is used to profile the Nt in E - ET higher than 1 eV. Extracted Nt profile shows a reasonable continuity between both approaches and looks like a Gaussian function.
Keywords :
Gaussian processes; NAND circuits; flash memories; 3D NAND flash memory; AC-gm method; AC-transconductance method; Gaussian function; electron volt energy 0.93 eV; electron volt energy 3 eV; nitride storage layer; retention characteristics; trap density; trap profiling; tube-type channel structure; Dispersion; Electron traps; Flash memories; Logic gates; Mathematical model; Nonvolatile memory; Tunneling; 3-D stacked NAND flash memory; AC- $boldsymbol {g}_{mathrm {mathbf {m}}}$ method; AC-gm method; Tube-type poly-Si body; cylindrical coordinate; nitride trap characterization; retention; tube-type poly-Si body;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2015.2419277