Optimization of Hetero-FET Alloy Composition for Low Noise Applications in Millimeter-Wave Frequency Range

The noise behavior of subquarter micrometer gate-length Hetero-FETs is investigated by using a rigorous two-dimensional physical simulator. The influence of device structure and operating conditions on the carrier transport inside the device and consequently on its noise performance is explained by making use of the microscopic nature of the model. 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 minimum noise figure in different frequency ranges.