טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentReznik Alla
SubjectConductivity and Structural Properties of Diamond and
CVD Diamond Films in Relation to the Presence of
Defects
DepartmentDepartment of Physics
Supervisor Professor Emeritus Rafael Kalish


Abstract

The application of diamond’s outstanding properties in electronics is limited due to various difficulties in diamond doping such as low doping efficiency, high carrier compensation and poor carrier mobility. The reason for these problems are studied in the present thesis. This study unambiguously shows that native defects are responsible for the degradation of semiconducting properties of diamond.

The thesis is devoted to the study of the various effects of defect (both introduced during film growth and those remaining after post-implantation annealing) on the electrical and structural properties of diamond. Two completely different regimes  of defect concentrations, namely above and below the graphitization threshold have been found and thoroughly studied by electrical and Raman measurements.

For heavily damaged diamond (defect concentration exceeds 1022 cm-3) the graphitization upon thermal annealing was studied. For slightly damaged diamond it is shown that point defects may themselves  cause the electrical conductivity that can be mistaken for real chemical doping. A model for such a defect related conductivity in  terms of the D- band conduction is proposed.

For semiconducting p-type B-doped diamond it was shown that point defects de-activate the B acceptor impurity. A model for vacancy-impurity interaction and a possible way to overcome the effect of defects by passivating them with H are suggested.