Characterization and Modeling of SH in Multi-Finger RF LDMOS Transistors Using BSIM-BULK Model

In this work, we present self-heating (SH) characterization and modeling of 130 nm Bipolar-CMOS-DMOS (BCD) technology node multi-finger Laterally Diffused Metal-Oxide-Semiconductor (LDMOS) transistors using extensive DC and S-parameter measurements. To accurately capture the impact of SH across a wide frequency range, we use a fourth-order thermal network within the industry-standard Berkeley Short-channel IGFET (BSIM)-BULK model framework. Additionally, we analyze the frequency behavior of RF bulk multi-finger LDMOS transistors and capture parasitic effects due to substrate and gate network. Our findings provide significant insights into LDMOS transistors. In particular, increasing the finger count reduces thermal resistance (by 6.6,∘C/Watt). Understanding how thermal resistance varies with finger count allows designers to optimize LDMOS layouts and mitigate SH effects. This leads to improved thermal management and more efficient, reliable RF devices.