SCR Structure Design For ESD Protection Of Bipolar Integrated Circuit

As integrated circuit (IC) is widely using in aerospace industry and other special fields, the ESD protection requirements of ICs have became higher and higher. Engineers have paid more attention to the ESD protection for CMOS IC because of the small critical dimension and low supply voltage. Resistor, diode, MOS transistor, bipolar transistor and silicon controlled rectifier (SCR) are used for ESD protection of CMOS IC, which have made the technology of ESD protection for CMOS IC tend to be mature. However, the ESD protection of bipolar circuit has not attracted designers'attention for its own ESD ability. Generally, the ESD robustness of bipolar circuit is between 500V and 2000V, which is far from meeting the requirements of aerospace industry.In this thesis, some works on ESD protection of bipolar integrated circuit have been done, which is based on a specific ESD protection requirement of bipolar circuit and standard bipolar technology of CETC-NO.24. The followings are the main content done in this thesis.Firstly, the traits of bipolar circuit are studied, and a kind of SCR structure is proposed. Then some parameters are optimized focused on the trigger voltage, holding voltage and second breakdown current by using TCAD, and the trigger voltage is affected by L-value which is the dimension between anode and cathode is found. In addition, mixed signal simulation which is under the HBM model of 2000V voltage is performed, and an SCR structure which has the ESD robustness voltage beyond 6KV is obtained.Secondly, based on simulation results, seven SCR layout cells with different L value have been designed, and the SCR cells have been taped-out using the product-line of CETC-NO.24.Finally, the testing of single-SCR samples using the ESD Zapmaster was done, seven SCR structures with different L value all passed 8KV HBM model test, and this SCR structures have become cells in B6035 standard cell library of ESD protection. It shows that this SCR structure will improve the ESD protection level in domestic, and preparae well for developing ICs which has high ESD robustness.