ملخص: The minority carrier diffusion length in a semiconductor device is a very important parameter for its design, understanding or modeling; usually this parameter is taken from graphs or tables made for uniform doping. Unfortunately in a real device the doping is rarely uniform and usually has a specific doping distribution (error function, Gaussian, etc...); the diffusion length for these distributions is difficult to evaluate, especially for heavy doping. In this paper we show how this parameter can be measured directly and precisely on localized regions of a device with any doping distribution. The method used is based on the Electron Beam Induced (EBIC) technique; we expose the experimental set up, the principle and discuss the conditions of the validity of the measurements. We have tried to measure the minority carrier diffusion length in the base region of two bipolar transistors with a Gaussian doping distribution and in an emitter region of an npn transistor with a heavy doping, error function-type distribution. The value of the minority carrier diffusion length found is compared with those available in the literature and the validity of the measurements is discussed.

لغة: إنجليزية