Understanding Linear-Mode Robustness in Low-Voltage Trench Power MOSFETs
Understanding Linear-Mode Robustness in Low-Voltage Trench Power MOSFETs
复制标题
了解低压沟槽功率 MOSFET 的线性模式鲁棒性
DOI：
10.1109/tdmr.2009.2036001
复制
发表时间：
2010
影响因子：
2
通讯作者：
P. Rutter
中科院分区：
文献类型：
--
作者：
O. Alatise;I. Kennedy;G. Petkos;K. Khan;A. Koh;P. Rutter
评估了低压分立功率沟槽 MOSFET 的高温电热稳定性和线性模式鲁棒性。线性模式稳健性取决于亚阈值扩散电流的正温度系数和 MOSFET 增益因子。功率 MOSFET 的数据表阈值电压温度系数 (V GSTX TC) 非常重要，因为它与器件的线性模式鲁棒性和零温度系数 (ZTC) 点相关。 MOSFET 有源面积和单元间距对 V GSTX TC 的影响在制造的器件上进行了实验评估。结果表明，V GSTX TC 的幅度随着 MOSFET 有源面积的增加而增加，而随着单元间距的增加而减小。对于相同的有源区域，热失控开始时的漏极电压随着 V GSTX TC 的减小而增加，从而使 V GSTX TC 成为线性模式鲁棒性的指标。尽管 ZTC 点处的栅极电压和 V GSTX TC 的幅度随着 MOSFET 有源面积的增加而增加，但热阻的降低提高了线性模式的鲁棒性。这意味着，在较低比导通电阻（R SPEC，以欧姆平方毫米为单位）方面提高器件性能是以牺牲功率 MOSFET 的线性模式鲁棒性为代价的，因为较低 R SPEC 器件具有较高的增益因子，并且在较弱的反转电平下提供较高的电流（因此包含较高比例的亚阈值扩散电流）。在设计功率 MOSFET 时，必须考虑这些参数，以尽量减少高温不稳定性并提高线性模式鲁棒性。
The high-temperature electrothermal stability and linear-mode robustness of low-voltage discrete power trench MOSFETs are assessed. The linear-mode robustness is shown to be dependent on the positive temperature coefficient of the subthreshold diffusion current and the MOSFET gain factor. The datasheet threshold voltage temperature coefficient (V GSTX TC) of a power MOSFET is important because it correlates with the linear-mode robustness and the zero-temperature-coefficient (ZTC) point of the device. The impact of the MOSFET active area and the cell pitch on the V GSTX TC is experimentally assessed on fabricated devices. It is shown that the magnitude of the V GSTX TC increases as the MOSFET active area increases, whereas it reduces as the cell pitch increases. The drain voltage at the onset of thermal runaway is shown to increase as the V GSTX TC reduces for the same active area, thereby making the V GSTX TC an indicator of linear-mode robustness. Although the gate voltage at the ZTC point and the magnitude of the V GSTX TC increase with the MOSFET active area, the reduced thermal resistance improves the linear-mode robustness. The implication is that improved device performance in terms of lower specific on-state resistance ( R SPEC in ohm-square millimeter) is at the expense of linear-mode robustness of the power MOSFET since lower R SPEC devices have higher gain factors and higher currents are delivered at weaker inversion levels (and therefore contain higher proportions of subthreshold diffusion currents). In designing power MOSFETs, these parameters must be taken into consideration so as to minimize high-temperature instability and improve linear-mode robustness.