Selective Metal Oxide Deposition Using Hydroxy Plasma Pre-Treatment
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Solution Overview
Problem
The downscaling of semiconductor devices is limited by edge placement errors and tiger tooth defects in extreme ultraviolet (EUV) lithography, leading to increased RC delay and device performance issues due to challenges in patterning small structures and landing metal via on metal lines in the back end of the line (BEOL).
Innovation Solution
A method involving low-temperature pre-treatment with a hydroxy species-generating plasma to selectively deposit metal oxide on exposed metal surfaces relative to dielectric materials, using plasma-enhanced processes like ALD or CVD, with inhibitors to create controlled electrical connections and patterned dielectric layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If EUV lithography is used for patterning small structures, then device scaling is enabled, but edge placement errors and tiger tooth defects increase
Solution Approach 1:
The patent applies preliminary action by performing plasma pre-treatment on metal surfaces before deposition. The plasma treatment modifies the metal surface chemistry and topography in advance, creating optimal conditions for subsequent metal oxide deposition. This preparatory step ensures precise edge placement and eliminates tiger tooth defects by establishing uniform nucleation sites across the metal surface, directly addressing the manufacturing precision issues in EUV lithography.
Solution Approach 2:
The patent utilizes parameter changes by controlling plasma treatment parameters (power, gas composition, treatment time) and deposition parameters (temperature, precursor flow rates, pressure) to achieve precise control over metal oxide formation. By optimizing these parameters, the process achieves uniform deposition with controlled thickness and composition, resolving the edge placement errors that occur during device scaling.
2Reliability
If metal via landing on metal lines is attempted in BEOL, then electrical connections are formed, but RC delay increases due to patterning challenges
Solution Approach 1:
The patent replaces conventional thermal oxidation methods with plasma-enhanced metal oxide deposition. This substitution allows for lower processing temperatures and better control over oxide thickness and uniformity. The plasma-enhanced process achieves complete metal surface coverage with controlled oxide thickness, ensuring reliable via-to-line connections while minimizing RC delay through precise dimensional control.
3Ease of manufacture
If selective deposition is performed without pre-treatment, then process simplicity is maintained, but deposition uniformity and nucleation quality deteriorate
Solution Approach 1:
The patent merges the plasma pre-treatment step with the deposition process by using the same plasma source for both surface modification and oxide formation. This integrated approach maintains process simplicity while achieving superior deposition uniformity. The plasma treatment and deposition are combined in a single continuous process, eliminating the need for separate treatment steps while ensuring high-quality nucleation and uniform metal oxide coverage.
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 reduces edge placement errors, improves device performance, and minimizes RC delay by ensuring precise deposition of metal oxides, thereby enhancing semiconductor manufacturing efficiency and reducing EUV lithography steps.
Implementation Method 1
contacting the substrate with a plasma generated from a hydrogen-containing source and an oxygen-containing source to generate hydroxy species
Implementation Method 2
the hydroxy species react with the dielectric material to form hydroxy-terminated dielectric material and with the metal surface to form an oxidized metal surface
Implementation Method 3
selectively depositing the metal oxide on the hydroxy-terminated dielectric material relative to the inhibited metal surface
Implementation Method 4
plasma-enhanced processes like ALD or CVD
Data Source
AI summary
Systems and methods of selectively depositing metal oxide on an exposed metal surface relative to a dielectric material on a substrate by pre-treatment with a hydroxy species-generating plasma prior to inhibition of the metal surface with an inhibitor, and subsequent metal oxide deposition on the dielectric material are disclosed. Exemplary inhibitors include low vapor pressure inhibitors. Exemplary systems include heated ampoules and gas lines for delivering inhibitors or other processing chemicals.