A method for forming a diffusion cooling hole in a substrate includes removing material from the substrate to form a metering section having an inlet on a first side of the substrate and removing material from the substrate to form a diffusing section that extends between the metering section and an outlet located on a second side of the substrate generally opposite the first side. The method also includes forming a feature on a substrate surface within one of the metering section and the diffusing section. Forming the feature includes depositing a material on the substrate surface and selectively heating the material to join the material with the substrate surface and form the feature.