PRODUCTION OF SEMIINSULATING LAYERS IN N-DOPED INP BY FE IMPLANTATION

A detailed study of Fe implantation and damage annealing in indium pho sphide is presented. The technological goal was to obtain thermally st able semi-insulating layers in n-type InP. Different characterization techniques were employed, including structural (x-ray diffraction, Rut herford backscattering spectrometry, and transmission electron microsc opy), chemical (secondary ions mass spectrometry), and electrical (cur rent-voltage) measurements. Both undoped and n-type (Sn) doped substra tes were implanted with Fe doses ranging from 5x10(11) to 2.2X10(14) c m(-2) and annealed at a temperature of 650 degrees C. The high doses u sed to compensate n(+) doping caused amorphization of the material. Th e reordering process of the amorphous layers and its influence on the Fe redistribution properties were studied in detail. The activation of the implanted Fe atoms after annealing was derived. Although the reco very process of the amorphized layer appears to be rather complex, our results show that good crystal quality and full compensation can be r eached also for n(+) doped substrates, leading to resistivity values a bove 2x10(7) Omega cm, even starting from an initial doping level as h igh as 1.4x10(18) cm(-3).