UHV-COMPATIBLE IN-SITU PRE-METALLIZATION CLEAN AND METALLIZATION OF SEMICONDUCTOR WAFERS

摘要

A method is provided of cleaning device surfaces for the metallization thereof by treating the surfaces in a chamber equipped for ionized physical vapor deposition or other plasma-based metal deposition process. The surfaces are plasma etched, preferably in a chamber in which the next metal layer is to be deposited onto the surfaces. Also or in the alternative, the surfaces are plasma etched with a plasma containing ions of the metal to be deposited. Preferably also, the etching process is followed by depositing a film of the metal, preferably by ionized physical vapor deposition, in the chamber. The metal may, for example, be titanium that is sputtered from a target within the chamber. The process of depositing the metal, where the metal is titanium, may, for example, be followed by the deposition of a titanium nitride layer. The process steps may be used to passivate the surfaces for transfer of the substrate containing the device surfaces through an oxygen or water vapor containing atmosphere or through another atmosphere containing potential contaminants such as through the transfer chamber of a cluster tool to which are connected CVD or other chemical processing modules. In the preferred embodiment, etching is achieved by maintaining a high ion fraction and high bombardment energy, for example, by applying a high negative bias to the substrate, operating the plasma in a net etching mode, then, by lowering the bombardment energy, for example by lowering the bias voltage, or by lowering the ion fraction, such as by increasing sputtering power, or decreasing plasma power, chamber pressure, a net deposition of the metal by IPVD is brought about.