Temperature Dependence of the Threshold Voltage Shift Induced by Carrier Injection in Integrated STI-Based LDMOS Transistors

摘要

Large threshold voltage shifts $(Delta V_{t})$ are experimentally observed in n-channel lateral DMOS transistors under high current–voltage regime. The effect is enhanced by the gate voltage as well as by the ambient temperature $(T_{A})$ . By approximating the curves with the usually adopted power-law dependence $(Delta V_{t} = At^{n})$, two different contributions are observed, and a clear increase of the exponent $n$ is found. A numerical investigation is carried out, revealing that the electric field normal to the oxide interface $(E_{n})$ as well as the internal temperature $(T)$ close to the source side of the MOS channel is mainly responsible for such enhanced degradation.