ABSTRACT
The type of etch feature formed depends on the attack of the bath. For those where material removal in the defects is more rapid than in the surroundings, etch pits result, while if etching is slower in the defects, hillocks will become apparent. Therefore, the defects are prominent and the level of dislocations due to the growth conditions or substrate deficiencies can be assessed. In addition, each bath requires that a certain thickness of the layer is etched away before these growth features are revealed. This thickness varies with the material to be characterized and the bath used. Through the use of a variety of baths and etching conditions, the weakness in the system can be reduced and even the finest layers can be characterized.
