[4] [4] DO K, KOO Y. A new SCR structure with high holding voltage and low on-resistance for 5-V applications ［J］. IEEE Trans Elec Dev, 2020, 67(3): 1052-1058.

[5] [5] KER M D, HSU K C. Overview of on-chip electrostatic discharge protection design with SCR-based devices in CMOS integrated circuits ［J］. IEEE Trans Dev Mater Reliab, 2005, 5(2): 235-249.

[6] [6] DONG S R, WU J, MIAO M, et al. High-holding-voltage silicon-controlled rectifier for ESD applications ［J］. IEEE Elec Dev Lett, 2012, 33(10): 1345-1347.

[7] [7] VASHCHENKO V A, CONCANNON A, BEEK M T, et al. High holding voltage cascoded LVTSCR structures for 5.5-V tolerant ESD protection clamps ［J］. IEEE Trans Dev Mater Reliab, 2004, 4(2): 273-280.

[9] [9] CHATTERJEE A, POLGREEN T. A low-voltage triggering SCR for on-chip ESD protection at output and input pads ［J］. IEEE Elec Dev Lett, 1991, 12(1): 21-22.