CoolMOS导通电阻分析及与VDMOS的比较

Theoretical Analysis of CoolMOS On-Resistance and Compared with Ron of VDMOS

为了克服传统功率MOS导通电阻与击穿电压之间的矛盾,提出了一种新的理想器件结构,称为超级结器件或CoolMOS,CoolMOS由一系列的P型和N型半导体薄层交替排列组成。在截止态时,由于p型和n型层中的耗尽区电场产生相互补偿效应,使p型和n型层的掺杂浓度可以做的很高而不会引起器件击穿电压的下降。导通时,这种高浓度的掺杂使器件的导通电阻明显降低。由于CoolMOS的这种独特器件结构,使它的电性能优于传统功率MOS。本文对CoolMOS导通电阻与击穿电压关系的理论计算表明,对CoolMOS横向器件:Ron.A=C.V2B,对纵向器件:Ron.A=C.VB,与纵向DMOS导通电阻与击穿电压之间Ron.A=C.V2B.5的关系相比,CoolMOS的导通电阻降低了约两个数量级。

To overcome the trade-off relationship between the on-resistance and breakdown-voltage of conventional MOS power devices, a new device concept called as ＂superjunction＂ or ＂CoolMOS＂ has been proposed. CoolMOS is made of alternately stacked p-and n-type, thin semiconductor layers. In the off-state, the fields induced by the depletion charge of both region types compensate each other to allow the doping in the n-region and p-region to be very high without causing a reduction of the breakdown-voltage. In the on-state, the heavy doping ensures the onresistance is low enough. Due to the novel structure of the CoolMOS, the device demonstrates significant superiority property over the conventional power MOSFET in static state, dynamic state, and forward including reverse biased safe operating area. A systematic theoretical analysis and calculation for the property of CoolMOS has been made and compared with that of VDMOS, The result indicates that the on-resistance and breakdown-voltage relationship of CoolMOS for lateral structure is：Ron · A = C · VB^2, for vertical structure is ：Ron · A = C · VB, which will be reduced to more than 2-power when compared with Ron·A = C · VB^2.5, the on-resistance and breakdown-voltage relationship of VDMOS.