Equivalent circuit and simulation method for high-voltage LDMOS device

Abstract

The invention discloses an equivalent circuit and a simulation method for a high-voltage LDMOS device. In a high-voltage LDMOS device structure, the substrate current of a lightly-doped drift region is obviously different from that of the traditional intrinsic MOSFET, and a standard SPICE BSIM3 model is incapable of accurately simulating the substrate current of the lightly-doped drift region of the high-voltage LDMOS. According to the equivalent circuit and the simulation method disclosed by the invention, the collision ionization current of the lightly-doped drift region is accurately simulated by externally connecting a current source, a source equivalent resistor and a drain equivalent resistor, thus improving simulation accuracy and reducing a circuit design cycle.

Description

technical field [0001] The invention relates to design simulation of semiconductor devices, in particular to an equivalent circuit of a high-voltage LDMOS device, and also relates to a simulation method of the high-voltage LDMOS device. Background technique [0002] Because LDMOS (Laterally Diffused Metal Oxide Semiconductor) has high breakdown voltage, low on-resistance and high process integration, LDMOS is widely used in power integrated circuits and RF circuit design. In the design of these circuits, an accurate physical LDMOS model is one of the key factors for a successful design. LDMOS device structure such as figure 1 As shown, the source is located in the P-type body region, and the drain lightly doped N-type well is also called the LDMOS drift region. The depleted region is resistant to high voltage, and the gate polysilicon covers from the gate oxide to part of the field oxygen on the N-type well of the lightly doped drain. The part of the gate polysilicon locat...

AI Technical Summary

Problems solved by technology

[0004] At present, standard simulation models such as BSIM (Berkeley Short channel Insulated gate field effect transistor Model Berkeley Short Channel Insulated Gate Field Effect Transistor Model) and PSP can only describe the low-voltage MOSFET, that is, the intrinsic MOSFET substrate current, but cannot describe the light parameter in LDMOS. The substrate current generated by the impurity drift region

Images