Modeling of the Variation of Lateral Doping (VLD) Lateral Power Devices via 1-D Analysis Using Effective Concentration Profile Concept

The VLD technique has introduced for the propose of achieving the ideal surface electric field via a non-uniformly doped drift region. Yet, the ideal doping profile is impossible to be fulfilled in practical thus breaking the optimized lateral breakdown characteristic. In addition, the conventional 2-D methods, due to its complexity, are impractical in both explaining its physical nature and providing designing guidance. In this paper, a simple 1-D methodology based on Effective Concentration Profile (ECP) theory is proposed to provide the physical insight of the VLD technique and quantitatively depict its breakdown characteristic. The VLD-ECP concept indicates that the perfectly even surface electric field can be obtained by adjusting the drift region doping dose equals to the Charge Appointment Line (CAL) so that all the charges in drift region contribute to the vertical depletion, thus the lateral structure being an equivalently P-I-N junction. Considering non-ideal doping profile of commercial devices, a designing optimization criterion is proposed to avoid the undesirable lateral breakdown. The analytical results obtained by the proposed model are found to be sufficiently accurate comparing with TCAD simulation results verifying the veracity and effectiveness of the proposed methodology.