Fracture Strength Measurement of Single Crystal Silicon Chips as a Function of Loading Rate during 3-Point Bending Test

The present article shows how the fracture strength of single crystal silicon chips, which are generally used as semiconductor devices, is influenced by loading rate variation during a 3- point bending test . It was found that the fracture strength of the silicon chips slightly increases up to 4% with increasing loading rate for loading rates lower than 20 mm/min. Meanwhile, the fracture strength of the chips hardly increases with increase of loading rate to levels higher than 40 mm/min. However, there was an abrupt transition in the fracture strength within a loading rate range of 20 mm/min to 40 mm/min. This work explains through microscopic examination of the fracture surface of all test chips that such a big transition is related to the deflection of crack propagation direction from the (011) [ ${\bar{1}}00$ ] system to the (111) [ ${\bar{2}}11$ ] system in a particular loading rate (i.e. from 20 mm/min to 40 mm/min).