Cleaning Composition for Semiconductor Post-Etch Residue Removal
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Solution Overview
Problem
Current cleaning compositions fail to effectively remove post-etch residue and titanium-containing hardmask materials from microelectronic devices with high selectivity for titanium nitride hard masks while controlling etch rates for aluminum nitride and maintaining compatibility with copper and low-k dielectric materials.
Innovation Solution
A composition comprising a tetraalkylammonium hydroxide or quaternary trialkylalkanolamine base, an oxidizer with a heterocyclic amine N-oxide, a corrosion inhibitor, and a combination of polyprotic acids or salts, including phosphorous-containing acids, which is diluted with an oxidizer to achieve high etch rate selectivity for titanium nitride hard masks, controlled etch rates for aluminum nitride, and low etch rates for copper and cobalt, while being compatible with low-k dielectric materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional cleaning compositions are used, then post-etch residue removal is achieved, but selectivity for titanium nitride hard masks is insufficient and etch rates for aluminum nitride and copper are not controlled
Solution Approach 1:
The patent modifies the chemical composition parameters by incorporating specific bases (tetraalkylammonium hydroxide or quaternary trialkylalkanolamine), oxidizers (heterocyclic amine N-oxide), corrosion inhibitors, and polyprotic acids with phosphorous. These parameter changes enable differentiated etch rates: high for titanium nitride hard masks, controlled low for aluminum nitride, and low for copper and cobalt, while maintaining compatibility with low-k dielectric materials.
Solution Approach 2:
The cleaning composition is formulated as a composite chemical system combining multiple functional components: a specific base, oxidizer, corrosion inhibitor, and polyprotic acid mixture. This composite approach allows the composition to simultaneously achieve high etch rate selectivity for titanium nitride while controlling etch rates for aluminum nitride, copper, and cobalt, and maintaining compatibility with low-k dielectrics.
2Productivity
If high etch rate for titanium nitride hard mask is achieved, then hard mask removal efficiency is improved, but etch rates for aluminum nitride and copper may increase uncontrollably
Solution Approach 1:
The cleaning composition exhibits local quality by differentiating its etching action across different materials. It achieves high etch rate locally for titanium nitride hard masks (improving productivity) while simultaneously maintaining controlled low etch rates for aluminum nitride, copper, and cobalt (ensuring manufacturing precision). This selective action is achieved through the specific combination of base, oxidizer, corrosion inhibitor, and polyprotic acids.
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 a high etch rate for titanium nitride hard masks, low etch rates for aluminum nitride and cobalt, and compatibility with low-k dielectric materials, ensuring efficient removal of post-etch residues and titanium-containing hardmask materials with controlled etching.
Implementation Method 1
a tetraalkylammonium hydroxide or quaternary trialkylalkanolamine base
Implementation Method 2
an oxidizer with a heterocyclic amine N-oxide
Implementation Method 3
a corrosion inhibitor
Implementation Method 4
a combination of polyprotic acids or salts, including phosphorous-containing acids
Data Source
AI summary
The disclosure relates to a cleaning composition that aids in the removal of post-etch residues in the production of semiconductors. There is provided a stock composition comprising: a tetraalkylammonium hydroxide base or a quaternary trialkylalkanolamine base; a corrosion inhibitor; and a combination of at least two or more polyprotic acids or salts thereof, wherein at least one said polyprotic acid or salt thereof contains phosphorous.