Effective Concentration Profile: A Novel 1-D Analysis of the Variation of Lateral Thickness (VLT) Lateral Power Devices

Abstract

The VLT technique features for its irregular thickness of drift region and therefore realize the even surface electric field even with a uniformly doped drift region. However, the sophisticated structure of the drift region also making 2-D methods impractical in both modeling and explaining VLT's physical nature. In this paper, based on the Effective Concentration Profile (ECP) theory, a simple but effective 1-D modeling methodology is proposed to provide physical insight into the VLT technique. The VLT-ECP concept indicates that by physically removing the region that above Charge Appointment Line (CAL), the charge contributes to the lateral depletion can be reduced to zero leading to an even surface electric field. Further, an optimization criterion is proposed to provide useful guidance for the designing of VLT lateral power devices in practice. The comparison between the analytical results obtained by the proposed model and TCAD simulations verified the veracity and effectiveness of the proposed methodology.

Keywords

• Variation of lateral thickness
• 1-D model
• effective concentration profile
• breakdown voltage
• lateral power device