CAJ | 학술논문

针对目前双极电路的ESD保护需求,引入SCR结构对芯片进行双极电路ESD保护.通过一次流片测试,发现加入SCR结构的电路芯片失效,SCR结构的I-V特性曲线未达到要求.从设计问题和工艺偏差两方面入手,分析了失效原因,通过模拟仿真,验证了失效是因为在版图设计时为节省版图面积,将结构P阱中NEMIT扩散区域边上用来箝位的电极开孔去掉造成的,并非工艺偏差导致的.通过二次流片测试,验证了失效原因分析的正确性,SCR器件结构抗ESD电压大于6 kV,很好地满足了设计要求.
침대목전쌍겁전로적ESD보호수구,인입SCR결구대심편진행쌍겁전로ESD보호.통과일차류편측시,발현가입SCR결구적전로심편실효,SCR결구적I-V특성곡선미체도요구.종설계문제화공예편차량방면입수,분석료실효원인,통과모의방진,험증료실효시인위재판도설계시위절성판도면적,장결구P정중NEMIT확산구역변상용래겸위적전겁개공거도조성적,병비공예편차도치적.통과이차류편측시,험증료실효원인분석적정학성,SCR기건결구항ESD전압대우6 kV,흔호지만족료설계요구.
SCR structure was used for ESD protection in bipolar IC. However, the first chip with SCR structure failed, which might be caused by layout design or process variation. Through simulation and analysis, it was found that the failure was due to the removal of clamping electrode opening at the edge of NEMIT diffusion zone in p-well, which was intended to reduce layout area. To validate the analysis, a second chip was fabricated and tested. Results showed that the SCR structure could achieve an ESD protection voltage above 6 kV, which perfectly meets the requirements of the design.