Post-CMP Cleaning Composition for Molybdenum Etch Inhibition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing post-CMP removal compositions unintentionally remove unacceptable levels of molybdenum from microelectronic device surfaces, leading to faults and pattern defects, especially at higher pH levels, while failing to adequately clean post-CMP residues.
Innovation Solution
Aqueous removal compositions with a pH greater than 10, comprising water, organic additives, cleaning additives, water-miscible organic solvents, and pH adjustors, combined with specific molybdenum etching inhibitors such as quaternary ammonium compounds, pyridinium compounds, and radical scavengers, effectively reduce molybdenum etching while maintaining residue removal efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high pH removal composition is used, then post-CMP residue removal efficiency is improved, but molybdenum etching increases
Solution Approach 1:
The patent introduces molybdenum etching inhibitors as intermediary substances that mediate between the high pH removal composition and the molybdenum layer. These inhibitors (such as benzotriazole, tolyltriazole, or phenylmercaptoacetic acid) form protective complexes with molybdenum ions, preventing excessive etching while allowing the high pH composition to effectively remove post-CMP residues. This intermediary mechanism resolves the contradiction by decoupling the residue removal function from the molybdenum etching side effect.
Solution Approach 2:
The patent modifies the chemical parameters of the removal composition by adding specific inhibitors that change the etching kinetics. By introducing substances that complex with molybdenum ions, the effective etching rate is reduced while maintaining the high pH environment necessary for residue removal. This parameter change approach allows simultaneous achievement of high productivity and reduced material loss.
2Loss of substance
If conventional removal composition is used, then molybdenum etching is reduced, but post-CMP residue removal is insufficient
Solution Approach 1:
The patent merges two previously separate functions into a single composition: the high pH base composition for residue removal and the molybdenum etching inhibitor for protecting the molybdenum layer. This combined formulation achieves both objectives simultaneously, resolving the contradiction between adequate residue removal and minimized molybdenum etching.
Solution Approach 2:
The removal composition is formulated as a composite system containing multiple functional components: a high pH base (such as ammonium hydroxide or tetramethylammonium hydroxide), cleaning agents, and specific molybdenum etching inhibitors. This composite material approach allows the composition to perform multiple functions - aggressive residue removal and selective molybdenum protection - thereby resolving the technical contradiction.
3Ease of operation
If pH is increased to improve cleaning, then molybdenum layer integrity deteriorates
Solution Approach 1:
The patent applies preliminary anti-action by adding molybdenum etching inhibitors that preemptively protect the molybdenum layer before the high pH composition can cause damage. These inhibitors form protective films or complexes on the molybdenum surface, creating a barrier that prevents the high pH environment from degrading the layer integrity. This preliminary protection mechanism allows effective cleaning while maintaining layer reliability.
Solution Approach 2:
The patent converts the potentially harmful high pH environment into a beneficial cleaning agent by combining it with etching inhibitors. The high pH provides strong cleaning power for residue removal, while the inhibitors neutralize the harmful effect on molybdenum. This transformation approach resolves the contradiction by making the high pH condition beneficial for cleaning while preventing its detrimental effects on the molybdenum layer.
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 compositions significantly inhibit molybdenum etching from microelectronic device surfaces, preserving the integrity of molybdenum layers while effectively removing post-CMP residues, even at high pH levels.
Implementation Method 1
a quaternary ammonium compound of Formula A... wherein Ar is a substituted or unsubstituted aryl group
Implementation Method 2
a radical scavenger selected from the group consisting of an hydroxybenzene, a pyrazolinone, a compound having an aminoxyl radical, a gluconolactone, a tertiary alkyl alcohol, and ascorbic acid
Data Source
AI summary
The present disclosure relates to removal compositions for at least partially removing post-chemical mechanical polishing (post-CMP) residues from the surface of a microelectronic device. The removal compositions comprise an aqueous base composition and various molybdenum etching inhibitors that reduce the amount of molybdenum removed from the surface of the microelectronic device compared to the aqueous base composition.