Reliability of high voltage/high power L/S-band Hbt technology

This paper presents the qualification methodology and results of an InGaP HBT process industrialised by UMS to cover high power L and S band applications. The high level of robustness of the technology has been demonstrated with RF test up to 9 dB compression without any degradation. MTTF of 12 FIT/mm² of semiconductor at a junction temperature of 175 °C have been demonstrated based on more than 560,000 component hours. Also, following the activation period, an asymptotic decrease of the Beta is pointed out both at WLR and long term reliability test and modelled by a Black law. Activation energy between 0.52 and 0.75 eV and a Black factor between 1 and 2 was found. An original and complete failure analysis methodology including NIR emission microscopy, FIB and TEM analysis, have been used to characterised infant mortality for which the root cause is attributed to the propagation through the base–emitter junction of dislocation in the epitaxy. Activation energy of 0.58 eV was determined for this mechanism.     

X- and Ku-band internally matched packaged GaAs f.e.t.

The design and performances of medium-power X- and Ku-band internally matched GaAs f.e.t.s are reported. With input-output v.s.w.r. lower than 2 : 1 over more than 20% bandwidth in the X-band and l0% in the Ku-band, 50 and 200 mW two-stage cascaded amplifiers have been realised with no matching circuit outside the packaged f.e.t. and with only one power supply.