Conformal films on semiconductor substrates

A method for depositing a layer of diffusion barrier or seed material on a semiconductor substrate having a recessed feature, the method comprising:

• performing a first net deposition cycle including
• depositing a first deposited layer of the diffusion barrier or seed material and
• etching the first deposited layer to form a first etched layer having a first net deposited thickness;
• and
• performing a second net deposition cycle including
• depositing a second deposited layer of the diffusion barrier or seed material the first etched layer and
• etching the second deposited layer to form a second etched layer over the first etched layer, the second etched layer having a second net deposited thickness, wherein the first net deposited thickness is greater than the second net deposited thickness and wherein no etching bias is applied to the semiconductor substrate during etching of the first deposited layer and wherein an etching bias is applied during etching of the second deposited layer.