An N-type 50 V RF LDMOS with a RESURF (reduced surface field) structure of dual field plates (grounded shield, or G-shield) was investigated. The effect of the two field plates and N-drift region, including the junction depth and dopant concentration, on the DC characteristics was analyzed by employing the Taurus TCAD device simulator. A high BV (breakdown voltage) can be achieved while keeping a low (on-resistance). The simulation results show that the N-drift region dopant concentration has an obvious effect on the BV and and the junction depth affected these values less. There is an optimized length for the second field plate for a given dopant concentration of the N-drift region. Both factors should be optimized together to determine the best DC characteristics. Meanwhile, the effect of the first field plate on the BV and can be ignored. According to the simulation results, 50 V RF LDMOS with an optimized RESURF structure of a double G-shield was fabricated using 0.35 µm technologies. The measurement data show the same trend as the TCAD simulation, where a BV of 118 V and of 26 ohm·mm were achieved.

中文翻译：

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双G-Shield 50 V RF LDMOS的直流特性优化

研究了具有双场板（接地屏蔽或 G 屏蔽）的 RESURF（减少表面场）结构的 N 型 50 V RF LDMOS。使用 Taurus TCAD 器件模拟器分析了两个场板和 N 漂移区对直流特性的影响，包括结深度和掺杂浓度。可以在保持低（导通电阻）的同时实现高 BV（击穿电压）。仿真结果表明，N-漂移区掺杂浓度对BV有明显影响，结深对这些值的影响较小。对于 N 漂移区的给定掺杂浓度，第二场板的长度是优化的。应同时优化这两个因素以确定最佳直流特性。同时，第一场板对 BV 的影响可以忽略不计。根据仿真结果，采用 0.35 µm 技术制造了具有双 G 屏蔽的优化 RESURF 结构的 50 V RF LDMOS。测量数据显示出与 TCAD 模拟相同的趋势，其中实现了 118 V 和 26 ohm·mm 的 BV。