Tantalum Amido-Complex Precursors for CVD TaN Barrier Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current tantalum precursors for semiconductor manufacturing, such as Ta amides and imides, face thermal stability issues, decomposing at temperatures above 80°C, which limits their effectiveness in forming reliable copper migration barrier structures in high-performance silicon integrated circuits.
Innovation Solution
Development of a tantalum compound with specific hydrocarbyl, alkyl, and silyl substituents, formulated in a solvent medium, which is thermally stable and suitable for chemical vapor deposition (CVD) and atomic layer deposition (ALD) processes, allowing for the formation of conformal and smooth barrier layers at temperatures below 400°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional Ta amides and imides are used as precursors, then deposition can proceed at lower temperatures, but the precursors decompose above 80°C limiting their effectiveness
Solution Approach 1:
The patent modifies the molecular structure of tantalum precursor compounds by changing ligand parameters - specifically using amido ligands with bulky hydrocarbyl groups (R1-R4) that stabilize the compound thermally. This structural parameter change allows the precursor to maintain stability at deposition temperatures up to 400°C while still enabling effective film formation
Solution Approach 2:
The invention creates composite molecular structures combining tantalum center with specific organic ligand systems (amido ligands with hydrocarbyl, alkyl, silyl substituents). This composite approach integrates the reactive tantalum core with thermally stable organic frameworks, achieving both reactivity for deposition and stability at elevated temperatures
2Manufacturing precision
If vapor deposition techniques are used to deposit barrier layers in vias and trenches, then conformal and smooth layers can be achieved, but suitable tantalum precursors are required
Solution Approach 1:
The patent adjusts precursor molecular parameters to optimize vapor deposition performance - the chosen amido ligands with specific steric bulk and electronic properties enable the precursor to deliver conformal coverage in high aspect ratio structures while maintaining thermal stability, addressing both the precision and adaptability requirements
3Productivity
If copper metallization is implemented in high performance silicon integrated circuits, then device performance improves, but copper migration becomes a reliability issue requiring barrier layers
Solution Approach 1:
The patent develops tantalum precursor compounds that serve as intermediaries to form barrier layers between copper metallization and silicon/dielectric substrates. These Ta-based barrier layers act as mediating structures that prevent copper migration while allowing the high-performance copper interconnects to function, thus resolving the reliability issue without sacrificing productivity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The new tantalum compound provides stable and effective deposition of tantalum-containing films, preventing copper migration and improving adhesion in semiconductor devices, while maintaining thermal stability and conformality, thus enhancing the reliability of copper metallization in semiconductor devices.
Implementation Method 1
chemical vapor deposition (CVD), atomic layer deposition (ALD), digital CVD, pulsed CVD
Implementation Method 2
chemical vapor deposition (CVD), atomic layer deposition (ALD), digital CVD, pulsed CVD
Data Source
AI summary
Tantalum compounds of Formula I hereof are disclosed, having utility as precursors for forming tantalum-containing films such as barrier layers. The tantalum compounds of Formula I may be deposited by CVD or ALD for forming semiconductor device structures including a dielectric layer, a barrier layer on the dielectric layer, and a copper metallization on the barrier layer, wherein the barrier layer includes a Ta-containing layer and sufficient carbon so that the Ta-containing layer is amorphous. According to one embodiment, the semiconductor device structure is fabricated by depositing the Ta-containing barrier layer, via CVD or ALD, from a precursor including the tantalum compound of Formula I hereof at a temperature below about 400° C. in a reducing or inert atmosphere, e.g., a gas or plasma optionally containing a reducing agent.