Linear Drain Current Degradation of ps-LDMOS Transistor Under Isubmax and Igmax Stress

The linear drain current (Idlin) degradations of the p-type symmetric lateral double diffused MOS (ps-LDMOS) transistor under the maximum substrate current (Isubmax) and the maximum gate current (Igmax) stresses are experimentally investigated for the first time. For the stress time , the Idlinincrease under the Igmaxstress is faster than that under Isubmaxstress because of more serious hot-electron injection happening at the bird's beak of source region, and the degradation mechanism and damage position are very different from that of the unsymmetric LDMOS. However, for the stress time longer than 1000 s, the Idlinbegins to decrease under the Igmaxstress resulting from the interface state dominating the degradation of channel region, whereas the Idlinstill keeps increasing under the Isubmaxstress because of the continuous hot-electron injection into the field oxide of drain drift region.