Thermo-reliability relationships of GaAs ICs

Thermal conductivity and failure mechanism activation energies are identified as being the key parameters for determining reliable application of GaAs ICs (integrated circuits). Differences from Si in these two areas cause no particular problems for the application of GaAs ICs, but they do require attention, especially when designing for and measuring long-term reliability. The liquid-crystal, diode-drop, and infrared measurement techniques for measuring temperature are examined, with empirical results shown for GaAs structures. The characteristics of these three methods are discussed and comparisons are made. Activation energies for GaAs and Si failure mechanisms are explained. The relationship of temperature and activation energy is provided. For example, +or-/-7 degrees C errors in measuring temperature can halve or double 150 degrees C device lifetimes for failure mechanisms with activation energies of 1.6 eV.<>