Dependence of mechanical on position in silicon ingoto by evaluating B and Ge codoped silicon

This paper reports characterization of mechanical properties of single crystal silicon with heavily-codoped boron (B) and germanium (Ge) as dopant impurities. We prepared three types of B and Ge codoped silicon sliced from the different ingot portion. The silicon device for tensile test was fabricated by using two steps of DRIE without high-temperature process up to 1000 °C. The experimental results revealed that the Young´s modulus and fracture strength was influenced by the portion, i.e. the concentration of the impurities, especially germanium concentration. SEM observation shows fracture initiated from the underside surface etched away by DRIE and formed (111) fracture surface.