Modeling the operation of field-effect transistors based on GaAs/AlGaAs heterostructures

The parameters of a structure consisting of a doped GaAs channel and an AlGaAs buffer located between the substrate and the channel are optimized using the Synopsys Sentaurus TCAD simulator. It is shown that the use of this buffer increases the breakdown voltage and power of the transistor compared to the basic structure transistor without an AlGaAs buffer. It is also shown that the transistor breakdown voltage is most greatly affected by the buffer composition (the fraction of aluminum in the Al x Ga 1− x As) solid solution and, that the maximum breakdown voltage is obtained for a buffer containing no less than 18% aluminum.