一种适合于OLED电视电源应用的新型超级结MOSFET

A Novel Superjunction MOSFET Suitable for OLED TV Power Application

提出了一种新型超级结MOSFET结构,通过优化Si表面漂移区的杂质分布以抑制器件的结型场效应管(JFET)效应,改善器件特性。首先通过技术计算机辅助设计(TCAD)模拟并对比了新型超级结MOSFET和现有超级结MOSFET的电场强度分布、栅漏耦合电容随漏极电压的变化和开关过程,发现600 V新型超级结MOSFET比现有600 V超级结MOSFET的击穿电压提高了15 V、比导通电阻减小约3%,开关特性得到了大幅改善,器件关断时漏极电压尖峰降低41 V,栅极电压尖峰降低10 V。该新型超级结MOSFET在国内晶圆制造平台上成功制作,获得了优异的器件性能。在300 W有机发光二极管(OLED)电视电源板上进行替代纵向双扩散MOSFET(VDMOSFET)的对比测试,发现电源系统使用该新型超级结MOSFET比使用现有超级结MOSFET,其电磁干扰(EMI)性能改善了4.32~5.8 dB;与使用VDMOSFET相比,在保持EMI性能同等水平的同时,系统效率提高了0.52%。

A novel superjunction MOSFET structure was proposed,and the device performance was improved by optimizing the doping profile in the drift zone near Si surface and suppressing the junction FET(JFET)effect.The electric field strength distribution,the change of the gain-drain coupling capacitance with the drain voltage,and the switching process of the novel superjunction MOSFET and conventional superjunction MOSFET were simulated and compared by technology computer aided design(TCAD).The simulation results show that compared with the 600 V convetional superjunction MOSFET,the 600 V new superjunction MOSFET has a 15 V higher breakdown voltage and 3%lower specific on-resistance.A significant improvement on the switching characteristics with 41 V reduction of the drain vol-tage spike and 10 V reduction of the gate voltage spike during the process of switching off.The new superjunction MOSFET was manufactured in the domestic wafer foundry,and excellent device performances were obtained.The new superjunction MOSFET was tested on a 300 W power board of an organic light emission diode(OLED)TV instead of a vertical double diffused MOSFET(VDMOSFET).It is found that the electromagnetic interference(EMI)performance of the power board using the new superjunction MOSFET is 4.32-5.8 dB better than that of the power board using the conventional superjunction MOSFET,and the system efficiency of the power board using the new superjunction MOSFET is improved by 0.52%while keeping the same EMI characteristic level.