A Novel Vertical Field Plate Lateral Device With Ultralow Specific On-Resistance

• Published in: IEEE transactions on electron devices 2014-02, Vol.61 (2), p.518-524
• Main Authors: Zhang, Wentong, Zhang, Bo, Qiao, Ming, Wu, Lijuan, Mao, Kun, Li, Zhaoji
• Format: Article
• Language: English
• Subjects: Breakdown voltage; Depletion; Devices; Dielectrics; Diffusion; Doping; Drift; Educational institutions; Electric potential; enhanced bulk depletion; Equations; Etching; Filled plastics; laterally diffused MOS; Mathematical models; Moss; R_{{\rm ON}; rm sp; Silicon; silicon limit; surface local depletion; vertical field plate (VFP); Voltage
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2013.2294643

A novel vertical field plate (VFP) lateral device with ultralow specific on-resistance (RON,sp) is proposed in this paper. The VFP surrounded by oxide is inserted in the bulk of the drift region. Compared to the surface local depletion of the conventional lateral field plate (LFP), the depletion layer of the VFP expands to the bulk of the drift region, which enhances the bulk electric field. Therefore, ultralow RON,sp is realized in the VFP device due to high drift-region doping (Nd) and short cell pitch. An analytical FP model is developed to describe the behavior of the VFP, in which the breakdown voltage (BV) and Nd are found to be proportional to the FP factor k. Then the uniform-doped VFP laterally diffused MOSs and the step-doped VFP laterally diffused MOS are proposed. The optimized device exhibits a BV of 945 V and a RON,sp of 34 mΩ·cm 2 which are superior to those of similar devices and the silicon limit.