 function of Ge content [Ohy96]. In addition, Roldan et al. [Rold98] have recently investigated the effects of 46 MeV proton irradiated induced trap generation and its impact on the electrical characteristics on SiGe HBTs from a state-of- the-art IBM BICMOS commercial technology. After 1014 cm protons (18.4 Mrad(Si) equivalent TID), the peak current gain (at 10 uA) was reduced by <8% and the maximum oscillation frequency and cutoff frequency showed only minor degradation. As we saw in the previous discussion of Si linear bipolar technology, the lateral pnp transistor exhibits an enhanced sensitivity to both TID and displacement damage. Recently Niu et al. investigated proton effects in gate-assisted lateral pnp (GLPNP) transistors from the advanced SiGe HBT BICMOS technology [Niu98]. They isolated the effects of proton induced bulk traps from those of surface traps and oxide charges in the GLPNP transistors that are widely used in BICMOS circuits [Niu98]. Negligible current gain degradation was observed for 46 MeV proton fluences of 1012 cm2. and the devices were still functional at 1013 cm2 The authors attribute the improved radiation hardness of this technology (as compared to conventional lateral pnp's) to the much thinner oxide and gate-assisted operation that minimizes the TID response. Clearly this technology is quite insensitive to both TID and displacement damage effects. 3.3.2 Charge Transfer Devices Silicon optoelectronic sensing arrays (visible, UV and x-ray) have been developed for a wide variety of scientific, commercial and military uses in space. They contain a matrix of up to several million photosensitive elements (or pixels) which generally operate by converting the photo-generated charge to a voltage that is multiplexed to a small number of output amplifiers. Present charge coupled devices (CCDs) are available with picoampere dark currents and charge transfer efficiencies (CTE) in excess of 0.999999 per pixel. During the development of these sensors, their susceptibility to ionizing radiation e