Title :
Plasma charging and mobile ions on the data retention of 0.25 μm flash memory
Author :
Liou, Jimmy Jih-Wei ; Pao-Chuan Lin ; Chen, Wei-Min ; Lin, James ; Huang, Chih-Jen ; Chen, Hwi-Huimg ; Hong, Gary
Author_Institution :
Specialty Technol. Div., United Microelectron. Corp., Hsin-Chu, Taiwan
Abstract :
Charge retention behavior affected by mobile ions and plasma charging, including charge loss and charge gain, are characterized on a flash cell with different test structures. Meanwhile, the Vt distribution for a cell array structure test (CAST) array is found to be influenced by program bake and erase bake. The amount of charge loss due to mobile ions for a single cell is around 3 V, which is much worse than the case for CAST arrays, being around 0.6 V. A special feature, charge gain, as much as 0.8 V after UV bake, reveals a wafer radial distribution. An interaction of plasma charging and mobile ions during wafer processing explains this interesting feature. Based on such a proposed physical model, the data retention behavior for various test structures can be well explained
Keywords :
flash memories; heat treatment; integrated circuit reliability; integrated circuit testing; integrated memory circuits; plasma materials processing; semiconductor process modelling; surface charging; surface treatment; CAST array; UV bake; cell array structure test; charge gain; charge loss; charge retention behavior; data retention; data retention behavior; erase bake; flash cell; flash memory; mobile ions; physical model; plasma charging; program bake; test structures; threshold distribution; wafer processing; wafer radial distribution; Electrostatics; Flash memory; Nonvolatile memory; Permittivity; Plasmas; Silicon compounds; Temperature distribution; Transconductance;
Conference_Titel :
Plasma- and Process-Induced Damage, 2001 6th International Symposium on
Conference_Location :
Monterey, CA
Print_ISBN :
0-9651577-5-X
DOI :
10.1109/PPID.2001.929982
