Patent ID: 8003528

Claim:
A method for forming a semiconductor structure, comprising: providing a substrate; forming a dielectric layer on the substrate; forming a conductor pattern on a main surface of the dielectric layer, the conductor pattern having a top surface and sidewalls; and performing a selective atomic layer deposition (ALD) process to selectively deposit a conformal metal layer only onto the top surface and sidewalls of the conductor pattern without depositing onto the main surface of the dielectric layer substantially; wherein the selective ALD process comprises the following steps: (1) flowing hydrogen-containing substance into a chamber for a period of time to adsorb hydrogen radicals on the main surface of the dielectric layer and on the conductor pattern; (2) pumping down the chamber while stopping all gas flow to selectively remove the hydrogen radicals merely from the main surface of the dielectric layer; (3) flowing tungsten precursor into the chamber at a low pressure and low temperature to react with the hydrogen radicals adsorbed on the conductor pattern, thereby selectively depositing a tungsten layer thereto; and (4) purging the chamber to remove by-products.