7.3.6 Laser ablation deposition
Another close cousin to sputter deposition is laser ablation deposition. Ion bombardment of the target is replaced by a focused pulse of light from an ultraviolet laser. Although each pulse may carry only 1 J of energy, this is delivered within 1 ns to a 1 mm spot on the target surface. This represents an astonishing power density and the target surface explodes into vapour that can be caught on the waiting wafer surface. It is vital to scan the focus point across the target surface or you will rapidly drill through it.
Laser ablation is a ‘quick and dirty’ method of film deposition which can operate under relatively poor vacuum conditions. It is most commonly used for depositing rare materials such as superconductors, where a full-sized target for other sputtering methods would be prohibitively expensive.