The influence of surface technological processes is reviewed with special emphasis on increased device reliability and lifetime. Surface quality plays a significant role in many degradation mechanisms because it influences all technological processes such as etching, metal evaporation and annealing as well as surface passivation quality. It is shown that such technological hardening is extremely important and could perhaps be performed by suitable surface technological processes such as etching, cleaning and brief chemical passivation. Lifetimes are also limited by electrical stress during the fabrication of the devices, during assembly of systems and during operation. To get satisfactory device protection at microwave frequencies there is a need to protect circuits against electrostatic discharges and transients. The development and properties of a promising new concept based on field emission switches are presented.