Most oxide, nitride, and silicide targets crack during normal sputtering. Applying (or removing) power to these types of targets, must be done by slowly ramping up / down with occasional ‘soaks’ to allow the target to recover from thermal stresses. Bonding such targets to a suitable backing plate are highly recommended to the target, once cracked, stays together. A cracked target will still be sputtered providing plasma has no line-of-sight access through the cracks to the bonding agent or the backing plate. Bonding the target to a backing plate may or may not allow it to accept a higher power. Remember, the characteristics of the bonding agent must now be added to the heat dissipation considerations.
