SYNTHESIS OF COPPER PRECURSORS WITH NITROGEN AND CARBON CONTAINING LEGANDS AND METHOD OF DEPOSITING COPPER THIN FILMS BY VAPOR PHASE
Publication Date: 2008-Jul-25
The IP.com Prior Art Database
Disclosed herein are non-limiting embodiments of volatile copper (I and II) complexes with nitrogen and carbon containing ligands. These new copper precursors are halogen and oxygen free. The volatile copper complexes are capable of selectively depositing a copper film onto a substrate surface under ALD or CVD conditions. The copper complexes are represented by general formula:
· Each R1 and R2 may be the same as or different from one another and each one is independently selected in the group consisting of H, C1-C6 linear or branched, alkyl, cycloalkyl, aryl, fluoroalkyl, alkylsilyl, arylsilyl, alkylamides, alkylsilylamides
· Each R3 is selected from the group consisting of H, C1-C6 linear or branched, alkyl, cycloalkyl, alkylsilyl, alkylamides, alkylsilylamides
· Each R4 and R5 may be the same as or different from one another and each one is independently selected in the group consisting of H, C1-C6 linear or branched, alkyl, cycloalkyl, alkene, aryl, alkylsilyl, arylsilyl, alkylamides, alkylsilylamides
· n is an integer representing the number of CH2 groups
· n = 1 or 2
Brief Description of the Prior Art
The current need for smaller geometry integrated circuits (IC) increases the demand for a denser packaging of circuits onto IC substrate. This requires the interconnections between components and dielectric layers be as small as possible and also reduction in the width of via interconnects and connecting lines. As the area of the interconnecting surface is reduced, the conductivity of interconnect is reduced, and thus resulting in increase in interconnect resistivity, which has become an obstacle in IC design. Due to unique properties (superior conductivity) of copper, it was selected over other metals (aluminum and tungsten) to reduce the size of lines and vias in an electrical circuit.
Depositing of copper by vapor phase deposition methods, such as metal-organic chemical vapor deposition (MOCVD) or atomic layer deposition (ALD) provides uniform coverage for the metallization. Metal compounds such as oxides, amides, halides, alkoxide, beta-diketonate and organometallic precursors are needed for deposition processes. The primary requirement for precursor to be suitable for vapor phase deposition process includes:
1. being liquid at room temperature or having low melting point
3. Thermal stability
4. High reactivity
Vapor phase deposition (MOCVD or ALD) of copper prec...