Gallium arsenide passivation method for the employment of High Electron Mobility Transistors in liquid environment

We report on effective prevention of GaAs corrosion in a cell culture liquid environment by means of polymerized (3-mercaptopropyl)-trimethoxysilane thin film coatings. Aging in physiological solution kept at 37 °C revealed no significant oxidation after 2 weeks, which is the typical period of incubation of a neuron cells culture. The method was also applied to High Electron Mobility Transistors (HEMT) arrays with unmetallized gate regions, in view of their application as neural signal transducers. Significant reduction of the degradation of the HEMT behavior was obtained, as compared to uncoated HEMTs, with good channel modulation efficiency still after 30 days aging