US Patent:
20050181226, Aug 18, 2005
Inventors:
Timothy Weidman - Sunnyvale CA, US
Ian Pancham - San Francisco CA, US
Dmitry Lubomirsky - Cupertino CA, US
Arulkumar Shanmugasundram - Sunnyvale CA, US
Farhad Moghadam - Los Gatos CA, US
International Classification:
B05C003/00
B05D001/18
US Classification:
428544000, 427437000, 118400000
Abstract:
A method and apparatus for electrolessly depositing a multilayer film using a fluid processing solution(s) that can clean and then electrolessly deposit a metal films having discrete or varying composition onto a conductive surface using a single processing cell. The process advantageously includes in-situ cleaning step in order to minimize the formation of oxides on the conductive surfaces, by minimizing or preventing the exposure of the conductive surfaces to oxygen (e.g., air) between the cleaning step and an electroless deposition process step(s). In one aspect, the chemical components used in the fluid processing solution(s) are selected so that the interaction of various chemical components will not drastically change the desirable properties of each of the interacting fluids, generate particles in the fluid lines or on the surface of the substrate, and/or generate a significant amount of heat which can damage the hardware or significantly change the electroless process results. In another aspect, no rinsing steps are required between the various deposition steps used to form the various layers, since the processing fluids are selected so that they are compatible with each other. In another aspect, throughout the process the conductive surfaces are continually in contact with various chemical components that will inhibit oxidation of the conductive surfaces and/or reduce the oxidized metal surfaces. In one aspect, a multilayer structure can formed on the surface of the conductive surface using the continuous electroless deposition process where the first layer of the multilayer structure has at least two of the following elements cobalt (Co), tungsten (W), phosphorus (P) or boron (B); and a second layer contains at least two of the following elements cobalt (Co), boron (B) or phosphorus (P). Formation of a multilayer structure on the conductive surface may have advantage since each deposited layer can have differing properties which when placed together will form a layer that has improved properties over a single deposited layer.