摘要
Amethod to analyze the kinetics of the charge accumulation in the tunnel oxide by the NAND flash memory program and erase (P/E) cycling is proposed. Both electron trapping and detrapping processes are required to be considered owing to the oxide high electric field during P/E cycles. Consequently, the electron trapping in the deep trap state is concluded, whose trap energy (E trap ) is more than 3.5 eV. Furthermore, the as-grown trap state density (N e ), the trapping capture cross section (σ ), and the number of trapped positive charges can also be extracted to explain the tunneling current modulation and the VT shift by oxide-Trapped charges under the P/E stress. The trapped electronsaremainly distributedin the centerof tunneloxide, and the distributed area extends as the P/E bias increases. In addition, the dependence of oxidation process is also shown. Both thermal dry and plasma oxidation have almost thesame value of σ (∼4×10 -17 cm 2 ).However,30% reduction of N5 e is shown in plasma oxidation (∼1.25×10 19 cm -3 ) when compared with thermal dry oxidation (∼1.88×10 19 cm -3 ).