Lifetime estimation of p-channel power VDMOSFETs applied in automotive applications

This paper presents research on the lifetime estimation of p-channel power VDMOSFETs, widely available in automotive and consumer applications. Lifetime and period of reliable work of these devices that present parts of the system also constraints the reliable operation mode of the system as a whole. Operation of these devices, especially operation under harsh conditions as in automotive applications, degrade VDMOSFET characteristics through time. Degradation of parameters leads to parametric failure of devices so that device no longer operates reliable, which is a problem for a consumer. Parameter of the VDMOSFETs that strongly impacts the lifetime is threshold voltage. Lifetime of devices used with different types of controlling signals is estimated using declared algorithms. Appropriate experiments have been carried out with the goal to obtain experimental data that can be used for the algorithms implementations. Experimental setup as well as estimation algorithms are discussed in detail in the paper. Usage of the signals is compared and further analyzed from the developers, as well as from the consumer’s standpoint.