Origin of 1/f noise in InAlAs/InGaAs HEMTs

For some applications (e.g.: mixers, oscillators), the 1/f noise upconversion limits the microwave performances of all kinds of HEMTs. That is why the origin of 1/f noise in HEMTs is highly needed. Previously it has been suggested that the channel is the main 1/f noise source at low drain bias. Recent experiments performed on different HEMT's structures indicated the InAlAs spacer and buffer as sources of 1/f noise. Some of these experiments also pointed to heterointerfaces as sources of 1/f noise. All these experiments quite clearly established the topology of the 1/f noise sources. A step further would be to answer which microscopic mechanism is responsible for the 1/f noise generation in a two-dimensional electron gas (2DEG). The purpose of this work is to identify lattice scattering as the microscopic source of 1/f noise in InAlAs/InGaAs HEMTs.