Selective Atomic Layer Deposition for Void-Free Feature Filling
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Solution Overview
Problem
Current thin film deposition methods, particularly atomic layer deposition (ALD), face challenges in completely filling features in microelectronic components as the feature size decreases, leading to hollow seams and device failure due to the inability to deposit metal-containing films uniformly and void-free, especially in smaller dimensions.
Innovation Solution
A super-conformal growth cycle in ALD is employed, using a metal-containing complex, purge gas, and co-reactant under specific conditions to selectively grow a metal-containing film, allowing for deposition, etching, and desorption, ensuring complete filling of features without voids by adjusting the deposition, etching, and desorption rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional ALD is used to deposit metal-containing films in small features, then film deposition occurs, but hollow seams form and complete filling is not achieved
Solution Approach 1:
The patent changes multiple process parameters including temperature gradients (higher at substrate, lower at source), pressure conditions, and precursor delivery timing to achieve super-conformal growth. These parameter changes enable the metal-containing complex to deposit, etch, and desorb in a controlled sequence that completely fills narrow features without hollow seams
Solution Approach 2:
The patent employs periodic delivery of the metal-containing complex followed by purge cycles. This periodic action allows repeated cycles of deposition and etching/desorption, ensuring complete feature filling while preventing hollow seam formation through multiple sequential layers
2Quantity of substance
If ALD is performed to fill narrow features, then film deposition occurs, but hollow seams remain in the middle portion of the feature
Solution Approach 1:
The patent converts the potential harm of incomplete filling and hollow seam formation into a benefit by using controlled etching and desorption processes. The metal-containing complex that would normally leave voids is instead used to etch away incomplete deposits and enable complete filling through repeated cycles, transforming the defect into a solution
3Manufacturing precision
If conventional deposition methods are used, then metal-containing films are deposited, but uniform deposition and complete feature filling cannot be achieved
Solution Approach 1:
The patent introduces dynamic control of deposition conditions including temperature gradients that vary spatially across the substrate and temporal variations in precursor delivery. This dynamic approach enables uniform deposition in narrow features while maintaining reasonable processing efficiency through optimized cycle times
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 method achieves selective and complete filling of features with a metal-containing film, preventing hollow seams and enhancing the reliability of microelectronic devices by ensuring uniform deposition even in narrow or deep features.
Implementation Method 1
The substrate is exposed to a WClx precursor and a reducing agent at a first set of conditions to deposit a first tungsten layer
Implementation Method 2
the metal-containing complex to: (i) deposit metal and etch the metal-containing film
Implementation Method 3
deposit metal, etch the metal-containing film and allow for desorption of the deposited metal from the metal-containing film
Data Source
Figure 1a~1b
Figure 2a~2d
Figure 3
AI summary
Methods of forming metal-containing films by atomic layer deposition are provided. The methods include delivering a metal-containing complex, a purge gas, and a co-reactant to a first substrate under sufficient conditions such that the metal-containing film selectively grows on at least a portion of the first substrate.