LDMOS热载流子注入效应安全工作区的研究

Study of High-carrier Injection Safe Operation Area for LDMOS Device

安全工作区(SOA)是MOSFET器件设计中的一个关键参数。传统CMOS在衬底电流-栅极电压曲线上只出现一个衬底电流峰值,该峰值可直接反映出热载流子注入(HCI)效应最强的位置,因此可以容易地给出其SOA;而对于横向双扩散MOSFET(LDMOS)器件,由于Kirk效应的发生,造成其衬底电流峰值不明显,此时的衬底电流已经不能再完全反映HCI效应的强弱,单纯使用Hu模式或衬底电流模式对SOA测试和分析都不合适。针对发生严重Kirk效应的LDMOS,此处提出一套更合理的HCI SOA测试方法,该方法既能节省测试时间,同时准确性又高。

Safe operation area（SOA） is a key parameter in MOSFET device design.For traditional CMOS,there is an only one subtract current peak in subtract current-gate voltage curve.The peak can directly reflect the best high- carrier injection （HCI） effect position, so it is easy to give its SOA.For lateral double-diffused MOSFET（LDMOS） de- vice, the peak of subtract current is not obvious due to Kirk effect, so subtract current can not fully reflect the strength of the HCI effect.Hu model or subtract current model is not appropriate for SOA test and analysis when purely used.One more reasonable HCI SOA test method is shown for LDMOS with serious Kirk effect which can save test time and be more accurate.