Method of removing an etch mask

An embodiment method includes forming a patterned etch mask over a target layer and patterning the target layer using the patterned etch mask as a mask to form a patterned target layer. The method further includes performing a first cleaning process on the patterned etch mask and the patterned target layer, the first cleaning process including a first solution. The method additionally includes performing a second cleaning process to remove the patterned etch mask and form an exposed patterned target layer, the second cleaning process including a second solution. The method also includes performing a third cleaning process on the exposed patterned target layer, and performing a fourth cleaning process on the exposed patterned target layer, the fourth cleaning process comprising the first solution.