Halogen-Inhibited Metal Deposition for Bottom-Up Recess Fill
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor manufacturing techniques face challenges in achieving conformal metal deposition within recessed features, leading to inadequate step coverage and metal fill.
Innovation Solution
The use of a halogen-containing deposition inhibitor is employed to modulate the metal deposition profile by reducing the deposition rate on selected substrate surfaces, allowing for improved step coverage and bottom-up metal fill in recessed features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional deposition methods (ALD or CVD) are used to deposit metal films, then deposition occurs on all substrate surfaces, but step coverage in recessed features is inadequate and field region deposition is excessive
Solution Approach 1:
The patent applies deposition inhibition selectively to different regions of the substrate. A halogen-containing inhibitor is used to modify the surface chemistry of the field region and upper sidewall areas, making them resistant to metal deposition, while the recessed feature bottoms remain unaffected and continue to accept metal deposition. This creates spatially varying deposition properties that achieve bottom-up fill without over-deposition in field regions.
Solution Approach 2:
The substrate is pre-treated with the halogen-containing deposition inhibitor before the metal deposition process begins. This preliminary modification of the substrate surface creates a protective layer or chemical modification that prevents metal precursor adsorption and subsequent deposition in inhibited regions, allowing controlled metal fill to occur only in desired areas during the subsequent deposition cycle.
2Productivity
If deposition rate is increased to improve productivity, then metal fill is faster, but conformality and step coverage deteriorate
Solution Approach 1:
By creating spatially selective inhibition zones, the patent allows different deposition rates in different regions. Inhibited regions (field areas) have zero or near-zero deposition rates, while non-inhibited regions (recessed feature bottoms) maintain normal deposition rates. This local differentiation enables use of CVD's inherently higher deposition rates while maintaining conformality in the critical recessed features through the inhibition mask effect.
3Manufacturing precision
If ALD is used to achieve conformal deposition with excellent step coverage, then deposition is limited by adsorbed reactant amounts, but the process is time-consuming and less productive
Solution Approach 1:
The halogen-containing compound acts as an intermediary substance that modifies the substrate surface properties. Rather than relying on the slow, sequential surface reactions of ALD, this intermediary creates a chemical barrier that passivates certain surface areas, preventing metal precursor adsorption and deposition. This mediator approach enables faster CVD-style deposition in non-inhibited regions while maintaining precision control through the selective inhibition pattern.
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 enables the deposition of conformal metal films with excellent step coverage and efficient filling of recessed features, even in high aspect ratio structures.
Implementation Method 1
the deposition inhibitor modifies a surface of the semiconductor substrate to make the surface more resistant to metal deposition than the surface was before modification
Implementation Method 2
exposing the semiconductor substrate to a metal precursor and a reducing agent to form a metal layer
Data Source
AI summary
Metal films, such as molybdenum films are deposited on a semiconductor substrate having one or more recessed features in a deposition process modulated by addition of a halogen-containing compound (e.g., an alkyl halide). In some implementations, a pre-treatment of a substrate with a halogen-containing compound is performed prior to contacting the substrate with a metal-containing precursor and a reducing agent. In some embodiments, the pre-treatment is performed such that the halogen-containing compound modifies the surface of the substrate to a greater degree in a field region of the substrate and near the opening of the recessed feature, as compared to the bottom portion of the recessed feature, where the modification of the substrate inhibits deposition of the metal. As a result, deposition of metals with improved step coverage can be achieved. In some implementations, modulation of deposition by halogen-containing compounds is used to achieve bottom-up metal growth in recessed features.