An effect of strain on transformation of irradiation-induced defects in MBE grown Si/SiGe layers is investigated. Pseudomorphic Si/SiGe layers are grown by MBE and implanted with H⁺, Ge⁺, Sn⁺ or As⁺ in either in-situ (during MBE growth) or ex-situ (in as-grown samples) conditions at different temperatures. The implantation is followed by high-temperature annealing. TEM is applied for the investigation of defect transformation. The following new effects will be presented and discussed in a systematic way:

-  Ion-driven self-organization of nano-particles, nano-voids and secondary defects in strain fields of Si/SiGe layers.

- Spatial separation of interstitials and vacancies by strain fields of pseudomorphic Si/SiGe QWs and formation of a new type of 2D I-V defect layers.

- Effects of dopant type and implantation temperature on defect evolution in Si/SiGe layered structure.

- Self-assembling of spherically shaped voids of nanometer size in thin SiGe QWs at room or elevated temperature of implantation.

- Monitoring of interstitials and vacancies in strained multilayer structures.

- Optical properties of the Si/SiGe strain layers with different structural defects.

The results are discussed in terms of spatial separation of the vacancies and interstitials in the strain field of the pseudomorphic Si/SiGe layered structure.