A Novel High Holding Voltage ESD device based on SCR and SiGe

Abstract

As a kind of efficient electrostatic protection device, SCR has been extensively used in on-chip electrostatic discharge protection for its strong current discharge ability and favorable internal radiating heat characteristic [1-7]. But there are low holding voltage and easy latch up happening two restrictions. A novel high-holding voltage ESD device based on SCR and SiGe is proposed in this paper. By introducing Ge composition in the P + region in the N-well of ordinary SCR, the holding voltage of the device is enhanced for that the current gain of the PNP parasitic transistor is reduced then the conductivity modulation is inhibited. The simulation results based on TCAD indicate that when Ge percentage composition is 30%, the holding voltage of new SCR with SiGe P+ region promotes four times from 2.06V to 10.32V. Therefore, there is no enlarging of the layout area of the novel structure when promoting the holding voltage and enhancing the anti-latch ability of SCR.