Metal β-diketiminate for Thin Film Deposition
Publication Date: 2015-Jan-14
The IP.com Prior Art Database
Methods of using metal β-diketiminate compounds having at least two β-diketiminate ligand for metal-containing deposition using strong reducing agent are provided. The method forms the metal-containing layer on a substrate (e.g., a semiconductor substrate or substrate assembly) using a vapor deposition process. The method may be useful in the manufacture of semiconductor structures.
The method includes: providing a substrate; providing a vapor including at least one compound of the general formula M(β-diketiminate)n (M being selected from Mn, Co, Ru, Fe, Ni, Cu and n=2 or 3): and contacting the vapor including the at least one compound of general formula M(β-diketiminate)n with the substrate (and typically directing the vapor to the substrate) to form a metal-containing layer on at least one surface of the substrate using a vapor deposition process. Suitable vapor deposition processes include ALD, CVD, PEALD, PECVD, cyclic-CVD or a combination thereof. Strong reducing agents are used to enhance the deposition mechanism. Those reducing agents are selected from but without limitation: NH3, DiMethyl Zinc (DMZ), DiEthyl Zinc (DEZ), TriMethyl Aluminum (TMA), Diborane and silane; the reducing agent being preferably DMZ. The strong reducing agent may be mixed with an inert gas, such as N2, Ar, He or H2.
A vapor comprising at least one metal-containing compound different than M(β-diketiminate)n (M being selected from Mn, Co, Ru, Fe, Ni, Cu and n=2 or 3) may also be provided and directed to the substrate. The metal of the at least one metal-containing compound different than M(β-diketiminate)n is selected from the group consisting of Ti, Ta, Bi, Hf, Zr, Pb, Nb, Mg, Al, and combinations thereof.
The formation of metal containing films via Chemical Vapor and Atomic Layer Deposition (CVD and ALD) is very challenging. Where diketiminate precursors are promising being thermally stable and volatile, enhancement of the deposition process is needed.
The use of strong reducing agent has several benefits. The strong reducing agent enhances the reaction mechanism allowing a higher growth rate and a faster reaction. The film quality is also greatly improved as well as the process window. Having a strong reducing gas allows reaction to occur at lower temperature which can be beneficial for deposition of Copper metal for instance where low temperature improve thin film continuity.
For the implementation of damascene copper interconnects for the new technology nodes, several diffusion barriers layer were considered. On of the commonly preferred barrier film is TaN/Ta bilayer. It is preferred because of its excellent adhesion to dielectrics and good barrier properties.
On top of this barrier, several liners or glue layers are considered to improve Copper wettability and prevent electromigration issues that increase when scaling semiconductor dev...