Ruthenium CMP Composition for High Removal Rate Control
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Solution Overview
Problem
Ruthenium is difficult to remove during chemical mechanical polishing (CMP) processes in the semiconductor industry, particularly in back-end-of-line (BEOL) applications, due to its chemical stability and unfavorable removal rates.
Innovation Solution
A CMP composition comprising a synergistic combination of ammonia and an oxygenated halogen compound, along with abrasives and acids, which oxidizes ruthenium and enhances its removal rate through mechanical action, with a pH range of 5 to 10.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional CMP compositions are used on ruthenium, then the chemical stability of ruthenium is maintained, but the removal rate becomes insufficient
Solution Approach 1:
The patent changes the chemical parameters of the CMP composition by introducing a synergistic combination of ammonia (basic) and oxygenated halogen compound (oxidizing). This parameter change enables the composition to achieve both high removal rates and controlled surface quality by modifying how the composition interacts with ruthenium's stable oxide layer
Solution Approach 2:
The invention uses a composite chemical system combining ammonia and oxygenated halogen compound rather than a single chemical agent. This composite approach creates synergistic effects where the combination produces higher removal rates than either component alone, while maintaining control over ruthenium's chemical stability
2Productivity
If stronger oxidizing agents are used to increase removal rate, then productivity improves, but surface quality and control become problematic
Solution Approach 1:
The patent carefully controls the oxidation potential by selecting specific oxygenated halogen compounds and adjusting their concentrations alongside ammonia. This parameter control allows achieving high removal rates while preventing excessive oxidation that would degrade surface quality
Solution Approach 2:
Ammonia acts as an intermediary that moderates the strong oxidizing action of the oxygenated halogen compound. The ammonia forms intermediate complexes with ruthenium oxide, controlling the oxidation process to maintain surface quality while enabling high removal rates through the synergistic interaction
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 composition achieves high and efficient removal rates of ruthenium from semiconductor substrates, effectively addressing the challenge of its chemical stability and facilitating its use as a next-generation interconnect material.
Implementation Method 1
an oxygenated halogen compound... which oxidizes ruthenium and enhances its removal rate
Implementation Method 2
along with abrasives and acids, which oxidizes ruthenium and enhances its removal rate through mechanical action
Data Source
AI summary
The compositions of the present disclosure polish surfaces or substrates that at least partially include ruthenium. The composition includes a synergistic combination of ammonia and oxygenated halogen compound. The composition may further include abrasive and acid(s). A polishing composition for use on ruthenium materials may include ammonia, present in an amount of 0.01 wt % to 10 wt %, based on the total weight of the composition; hydrogen periodate, present in an amount of 0.01 wt % to 10 wt %, based on the total weight of the composition; silica, present in an amount of 0.01 wt % to 12 wt %, based on the total weight of the composition; and organic sulfonic acid, present in an amount of 0.01 wt % to 10 wt %, based on the total weight of the composition, wherein the pH of the composition is between 6 and 8.