Randomness and Statistical Laws of Indentation-Induced Pop-Out in Single Crystal Silicon.

Randomness and discreteness for appearance of pop-out of the single crystal silicon with a (100) orientation were studied by a self-made indentation device. For a given maximum penetration load, the load for appearance of pop-out fluctuates in a relatively large range, which makes it hard to study the effect of the loading/unloading rate on the load . Experimental results with different maximum penetration loads indicate that the critical penetration load for appearance of pop-out is in the range of 15 mN20 mN for the current used single crystal silicon. For a given maximum penetration load, the load for appearance of pop-out seems random and discrete, but in the point of statistics, it has an obviously increasing trend with increase of the maximum penetration load and also the fraction / approximately keeps in the range of 0.20.5 for different maximum penetration loads changing from 15 mN to 150 mN.