Effects of heavy phosphorus-doping on mechanical properties of Czochralski silicon

The mechanical properties including hardness, Young’s modulus, and fracture toughness of heavily phosphorus (P)-doped Czochralski (Cz) silicon have been investigated by means of nanoindentation and microindentation. In view of the results of nanoindentation characterization, it is derived that the hardness of heavily P-doped Cz silicon is essentially the same as that of lightly P-doped Cz silicon. While, the Young’s modulus of Cz silicon is to a certain extent decreased by the heavy P-doping. With the same microindentation load, the lengths of the radial and lateral cracks in the heavily P-doped silicon are shorter than those in the lightly P-doped silicon, indicating that the heavily P-doped Cz silicon possesses a higher indentation fracture toughness.