A computationally efficient unified approach to the numerical analysis of the sensitivity and noise of semiconductor devices

This paper presents a new computationally efficient unified approach to the numerical simulation of sensitivity and noise in majority-carrier semiconductor devices, based on the extension to device simulation of the adjoint method, well known in the sensitivity and noise analysis of electrical networks. Sensitivity and device noise analysis based on physical models are shown to have a common background, since they amount to evaluating the small-signal device response to an impressed, distributed current source. This problem is addressed by means of a Green’s function technique akin to Shockley’s impedance field method. To enable the efficient numerical evaluation of the Green’s function within the framework of a discretized physical model, interreciprocity concepts, based on the introduction of an adjoint device, are exploited. Examples of implementation are discussed, relevant to the sensitivity and noise analysis of GaAs MESFET’s.