The present application is a national-stage entry under 35 U.S.C. § 371 of International Patent Application No. PCT/KR2018/016739, filed Dec. 27, 2018, which claims priority to Korean Patent Application No. 10-2018-0165373, filed Dec. 19, 2018, the entire disclosure of each of which is incorporated by reference herein.

TECHNICAL FIELD

The present invention relates to a vapor deposition compound enabling thin-film deposition through vapor deposition, and more particularly to a novel cobalt precursor, which may be applied to atomic layer deposition (ALD) or chemical vapor deposition (CVD) and exhibits superior reactivity, volatility and thermal stability, a method of preparing the same, and a method of manufacturing a thin film using the same.

BACKGROUND ART

In an atomic layer deposition (ALD) process or a chemical vapor deposition (CVD) process of forming an insulating film, a conductive thin film, or the like through a surface reaction using a precursor on a wafer, the selection of an appropriate precursor is regarded as very important, along with the process apparatus.

In the case of cobalt, there is no problem of increasing contact resistance due to the formation of cobalt boride (CoB), and moreover, relatively low resistivity when forming a cobalt silicide layer may be exhibited, and superior thermal stability may also be exhibited, and thus research is ongoing into the use of cobalt silicide as an ohmic contact layer in next-generation semiconductor processes.

In particular, as the extent of integration of semiconductor devices increases and the structure thereof becomes more complicated, a cobalt thin film having a structure having a high aspect ratio and superior step coverage is required.

Moreover, a cobalt oxide thin film is expected to be useful in various fields such as those of magnetic detectors, moisture sensors, oxygen sensors and superconductors. In addition, studies have been actively conducted with the goal of improving the adhesion between a copper thin film and a diffusion barrier layer using a metal cobalt thin film as an adhesive layer.

Examples of a generally used precursor compound for cobalt deposition broadly include Co(CO)3(NO) [cobalt tricarbonyl nitrosyl], Co(CO)2Cp [cobalt dicarbonyl cyclopentadienyl], Co2(CO)8[dicobalt octacarbonyl], CoCp2[bis-cyclopentadienyl cobalt], and the like.

Of these, Co(CO)3(NO) or Co(CO)2Cp compounds are liquid at room temperature and have the advantage of considerably high vapor pressure, but cause many difficulties during processing because they are thermally unstable, exhibiting pyrolysis at room temperature. Also, Co2(CO)8and CoCp2compounds are solid at room temperature and have relatively low vapor pressure, making them more difficult to apply to processing than the compounds Co(CO)3(NO) and Co(CO)2Cp.

Moreover, cyclopentadienyl-based compounds are problematic because of relatively high deposition temperatures of 300° C. or more and severe carbon contamination caused by the decomposition of the ligand.

In order to solve these problems, studies on cobalt precursors including diazadiene (DAD) ligands containing C═N double bonds or precursors including neutral ligands are underway, but there is an urgent need for research into cobalt precursors having superior reactivity, volatility and thermal stability, which may be utilized in various deposition processes.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been devised keeping in mind the problems of cobalt precursors encountered in the related art, and an objective of the present invention is to provide a cobalt precursor compound suitable for use in thin-film deposition, having superior reactivity, thermal stability and volatility.

Another objective of the present invention is to provide a method of manufacturing a thin film using the cobalt precursor compound.

However, the objectives of the present invention are not limited to the foregoing, and other objectives not mentioned herein may be clearly understood by those skilled in the art through the following description.

