Patent ID: 7851377

Claim:
An atomic layer deposition (ALD) method, the method comprising: placing a semiconductor wafer into a reaction chamber; pulsing a reactant in a gaseous form into the reaction chamber; applying a light on the reactant in the reaction chamber and before the reactant reaches the semiconductor wafer, wherein the light is not applied on the semiconductor wafer; reacting the reactant to form a film on the semiconductor wafer; performing a purging step to the reaction chamber; and performing a plurality of repeated cycles, with each of the cycles comprising: a first cycle comprising: pulsing the reactant in the gaseous form into the reaction chamber; and reacting the reactant to increase a thickness of the film, wherein the light is applied during the step of pulsing the reactant in the first cycle; and a second cycle comprising: pulsing the reactant in the gaseous form into the reaction chamber; and reacting the reactant to increase the thickness of the film, wherein the light is not applied during the step of pulsing the reactant in the second cycle.