The objective of the CERN RD50 Collaboration is to improve the radiation tolerance of semiconductor sensors used in high-energy physics experiments. CERN Research Board approved the Collaboration in June 2002. It currently consists of 55 member institutes and about 280 scientists. Each collaborating institute is participating in at least one of the RD50's six research lines. These research lines cover a large variety of studies on radiation hardness and radiation effects, including defect modelling, defect characterization, defect engineering, characterization of macroscopic effects, new materials, and full-size semiconductor detectors. In this paper, we concentrate on the defect engineering activities of the RD50. The latest experimental results of the defect engineered radiation hard detectors are presented.