Highly conductive buried n+ layers in lnp:fe created by MeV energy Si,S, and Si/S implantation for application to microwave devices

To obtain highly conductive buried layers in InP:Fe, MeV energy Si, S, and Si/ Simplantations are performed at 200°C. The silicon and sulfer implants gave 85 and 100 percent activation, respectively, for a fluence of 8 × 10¹⁴ cm⁻². The Si/S co-implantation also gave almost 100 percent donor activation for a fluence of 8 × 10¹⁴ cm⁻² of each species. An improved silicon donor activation is observed in the Si/S co-implanted material compared to the material implanted with silicon alone. The peak carrier concentration achieved for the Si/S co-implant is 2 × 10¹⁹ cm³. The lattice damage on the surface side of the profile is effectively removed after rapid thermal annealing. Multiple-energy silicon and sulfur implantations are performed to obtain thick and buried n⁺ layers needed for microwave devices and also hyper-abrupt profiles needed for varactor diodes.