Metalorganic Precursor Design for Copper ALD on SiO2
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current atomic layer deposition (ALD) methods are limited by the availability of chemical precursors with suitable thermal stability, reactivity, and vapor pressure, making it challenging to deposit thin metal films with precise control, especially for metals like copper which do not nucleate well on SiO2 surfaces.
Innovation Solution
A method involving compounds with specific formulae, such as [M(Si(R0)3)m(L1)p], where M is a transition metal, is used to form metal films through atomic layer deposition by contacting a substrate with vapor of these compounds to adsorb or react, followed by a second compound to form a metal film, optimizing the deposition process for improved thin film formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional ALD methods are used with limited chemical precursors, then the process is simple, but the film thickness control and metal deposition quality deteriorate
Solution Approach 1:
The patent changes the chemical parameters of the precursor compounds by developing new metalorganic compounds with specific molecular structures (formula 1) that have optimized thermal stability, reactivity, and vapor pressure. This allows achieving better film thickness control and metal deposition quality without increasing process complexity
Solution Approach 2:
The patent uses composite chemical structures combining metal centers with organic ligands (siloxane bridges and donor ligands) to create precursors that exhibit both thermal stability for controlled decomposition and appropriate reactivity for metal film formation. This composite approach resolves the contradiction between simplicity and performance
2Reliability
If copper is deposited directly on SiO2 surfaces, then the process is straightforward, but the adhesion and nucleation quality worsen
Solution Approach 1:
The patent applies preliminary action by using the new metalorganic precursors to form adherent copper seed layers on SiO2 surfaces before subsequent copper deposition. The precursors chemically interact with the substrate surface to create nucleation sites, ensuring reliable copper adhesion without requiring complex surface treatment processes
Solution Approach 2:
The metalorganic precursor compounds act as intermediaries between the copper metal and SiO2 substrate. These compounds decompose to form transition metal oxides or intermediate layers that promote copper nucleation and adhesion, eliminating the need for complex seed layer processes while improving reliability
3Manufacturing precision
If existing ALD precursors are used, then the process is well-established, but the thermal stability and reactivity are insufficient for precise thin film deposition
Solution Approach 1:
The patent systematically changes the thermal and chemical parameters of the precursors by designing molecules with specific ligand structures (siloxane bridges, donor ligands) that tune the decomposition temperature and reactivity. This enables precise control of thin film deposition while maintaining adequate thermal stability during the ALD process
Solution Approach 2:
The patent creates dynamic balance in the precursor design by ensuring the precursors have sufficient thermal stability to survive ALD processing conditions but also contain labile bonds that break at controlled rates to release metal atoms for film growth. This dynamic property resolution enables precise thin film deposition
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
This approach enhances the ability to form thin metal films with precise control, overcoming the limitations of existing ALD methods by providing improved thermal stability and reactivity, enabling the deposition of metals like copper on challenging substrates with better adherence and film quality.
Implementation Method 1
contacting the substrate with vapor of a compound having formula 1 such that at least a portion of the vapor of the compound having formula 1 adsorbs or reacts with a substrate surface to form a modified surface
Implementation Method 2
contacting the modified surface with a vapor of a compound having formula MLo to react and form at least a portion of the metal film
Data Source
AI summary
A method comprises contacting a compound having formulae (1) with a compound having formula MLo to form a metal:[M(SiR3)m(L1)p]n (1)whereinM is Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, a second row transition metal or a third row transition metal;R are each independently H, C1-C6 alkyl or —Si(R″)3;R″ are each independently H or C1-C6 alkyl;m is an integer from 1 to 3;n is a number representing the formation of aggregates or polymeric material;L1 is a neutral donor ligand;L is a ligand;p is an integer from 0 to 6; ando is an integer representing the number of ligands bonded to MLo.