Structural and electrical properties of oxygen complexes in Cz and FZ silicon crystals implanted with carbon ions

We present a comparative study of thermal donor (TD) center formation mechanisms as a result of carbon ion implantation into float zone (FZ-Si) and Czochralski (Cz-Si) silicon crystals. The kinetics of the TD center formation and transformation of their structure during annealing have been investigated. Also, the TD center formation takes place after additional oxygen implantation into FZ/Cz-Si, and an important role of recoil oxygen atoms (from the screen oxide) has been demonstrated for the FZ-Si case. Their concentration in the Si surface layer depends on the implantation dose and the screen oxide thickness, reaching up to values 10 18 to 10 19 cm �3 , which is comparable with the oxygen concentration in Cz-Si. These oxygen atoms can lead to additional thermal donor centers generation, especially in the FZ-Si.