This thesis investigates the evaluation of the minority carrier lifetime extraction model by using a numerical based device simulator, Medici. It is the aim of this thesis to evaluate on the accuracy of the analytical lifetime extraction model.
To understand the response of a p-n junction diode under transient condition, the fundamental physics of carrier drift, diffuse, generation and recombination is introduced. The forward bias and reverse bias responses of a diode is discussed prior to the introducing of the turn-off transient response. It is from this transient response of a diode allows the minority carrier lifetime to be determined.
The use of Medici to simulate the transient response of a p-n junction diode is discussed. The numerical result obtained from the simulation is used in the chargecontrol model for the calculation of the minority carrier lifetime. It is found that, when compare this calculated lifetime to the lifetime used in the simulation, one can found a huge difference between the two. This difference is analysed and is determine to be caused by the back contact recombination effect, which take place at the contact of the diode. The result obtained from the charge-control model has found to have a positive proportionally with the increase of the device length. From the simulation result, one can determine that, with the increase of the device length, the accuracy of the lifetime improves when it is compared to the expected lifetime.
Thus, the evaluation can be concluded that the charge-control model for the lifetime extraction technique is not accurate enough. The reason has been that, it does not consider the back contact recombination effect on the transient response, therefore, results the inaccuracy on the lifetime for a short device.