A computationally efficient self-consistent model for characterizing the operation and optimizing the structure of heterostructure field effect transistors (hetero-FETs) is introduced. Using this model one can accurately determine quantization effects inside devices which have complicated structures and different compound materials. The model will be applied to show how the layer structure of different Hetero-FETs can be optimized in order to improve their performance at high frequencies of operation.
The influence of alloy composition on the noise behavior of heterostructure semiconductor devices is investigated by using a rigorous two-dimensional physical simulator. The model takes into account non-stationary transport properties and quantization effects to allow a better understanding of the carrier transport properties inside the heterostructure devices and consequently to explain the noise performance of these devices by making use of the microscopic nature of the model. As an example, the model is applied to study the effects of alloy composition and the resulting band discontinuity on the 2DEG properties and on the noise performance of Hetero-FETs at millimeter-wave frequencies, and to extract the optimum alloy composition which leads to the minimum noise figure in different frequency ranges.
Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.