Selective Aluminium Compound Etching for Low-k and Copper Layers
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Solution Overview
Problem
Existing etching processes struggle to selectively remove thin or ultra-thin layers of aluminium compounds without damaging adjacent low-k materials, copper, or cobalt layers, which are crucial in semiconductor manufacturing.
Innovation Solution
A composition comprising solubilizers, etchants with fluoride anions, corrosion inhibitors, and chelating agents is used to selectively etch layers of aluminium compounds, ensuring precise control and minimal impact on nearby low-k materials and metal layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching processes are used to remove aluminium compound layers, then the etching speed may be sufficient, but the selectivity is poor causing damage to adjacent low-k materials, copper, or cobalt layers
Solution Approach 1:
The patent modifies the chemical composition parameters of the etching solution by incorporating specific organic acids (formic acid, acetic acid, propionic acid, butyric acid), their esters, and peroxides in controlled concentrations. This chemical parameter optimization enables high selectivity for aluminium compounds while preserving low-k materials, copper, and cobalt layers, resolving the contradiction between etching speed and selectivity
Solution Approach 2:
The etching solution employs a composite chemical system combining multiple organic acids, esters, and peroxides working synergistically. This composite formulation provides both the necessary etching power for aluminium compounds and the selectivity control to protect adjacent sensitive layers, achieving both high productivity and manufacturing precision
2Productivity
If aggressive etching compositions are used to increase etching speed, then productivity improves, but the integrity of low-k materials and metal layers is compromised
Solution Approach 1:
The patent carefully controls the concentration parameters of active etching components (organic acids, esters, peroxides) to achieve optimal etching speed while maintaining layer integrity. The specific ratio and concentration ranges of these components are optimized to provide sufficient etching power without causing damage to sensitive adjacent layers
Solution Approach 2:
The organic acids and esters act as intermediary substances that mediate the etching reaction. They provide controlled reactivity toward aluminium compounds while being less aggressive toward low-k materials and metal layers, thus enabling high productivity without compromising reliability
3Manufacturing precision
If selective etching is achieved through multiple process steps, then manufacturing precision improves, but the complexity of the manufacturing process increases
Solution Approach 1:
The patent combines multiple etching functions (selectivity control, etching speed, and layer protection) into a single integrated etching solution formulation. This merging of functions into one process step achieves high manufacturing precision without increasing process complexity, as the selective action is built into the chemistry of the single etching composition rather than requiring sequential processing steps
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 highly controlled and specific etching of aluminium compound layers, maintaining the integrity of low-k materials and metal layers, even for thin or ultra-thin layers, thereby enhancing the precision and reliability of semiconductor manufacturing processes.
Implementation Method 1
a composition for selectively etching a layer comprising an aluminium compound, preferably a layer comprising aluminium oxide, in the presence of a layer of a low-k material and/or a layer comprising copper and/or cobalt
Data Source
AI summary
A composition for selectively etching a layer including an aluminum compound in the presence of a layer of a low-k material and/or a layer including copper and/or cobalt, and a corresponding process, are described. Further described is a process for the manufacture of a semiconductor device, including the step of selectively etching at least one layer including an aluminum compound in the presence of a layer of a low-k material and/or a layer including copper and/or cobalt by contacting the at least one layer including an aluminum compound with the described composition.