Boron Nitride Mask Opening for Uniform Carbon Hardmask Etching
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Solution Overview
Problem
Conventional etching processes using silicon-containing materials for semiconductor manufacturing face issues with clogging and redeposition, leading to inconsistent and nonuniform etching of underlying mask materials, particularly in high aspect ratio features, which necessitate additional flash steps and reduce throughput.
Innovation Solution
Employing a boron-and-nitrogen-containing material as a mask overlying carbon-containing materials, utilizing oxygen-containing and fluorine-containing plasma effluents to selectively etch the carbon-containing material while minimizing etching of the boron-and-nitrogen-containing material, with controlled plasma conditions to maintain circularity and uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching processes use silicon-containing materials, then etching can be performed, but clogging and redeposition occur leading to inconsistent etching and reduced throughput
Solution Approach 1:
The patent changes the material parameter of the mask from conventional silicon-containing materials to boron-and-nitrogen-containing materials. This material substitution fundamentally alters the etching behavior, eliminating clogging and redeposition issues that plague silicon-based masks, thereby achieving both uniform etching and high throughput without compromise
Solution Approach 2:
The invention uses composite material composition (boron and nitrogen elements) in the mask layer to achieve superior performance. The boron-and-nitrogen-containing material exhibits unique properties that prevent the clogging and redeposition phenomena, resolving the contradiction between etching quality and manufacturing efficiency
2Manufacturing precision
If wet HF etch is used, then selective removal of material is achieved, but penetration into constrained holes is difficult and deformation of remaining material occurs
Solution Approach 1:
The patent replaces wet chemical etching with plasma-based etching processes. The plasma effluents provide both chemical reactivity for selective removal and physical momentum for penetration into constrained geometries, eliminating the limitations of wet HF etch while maintaining material selectivity
Solution Approach 2:
The invention changes the physical state and delivery mechanism of the etchant from liquid HF to plasma-phase reactive species. This parameter change enables the etchant to penetrate constrained holes effectively while maintaining selective removal of the carbon-containing material without deforming remaining structures
3Ease of operation
If dry etch with local plasma is used, then penetration into constrained holes improves and deformation decreases, but substrate damage occurs through electric arcs
Solution Approach 1:
The boron-and-nitrogen-containing mask material serves as an intermediary that modifies the plasma interaction with the substrate. This intermediate layer enables effective etching of the carbon-containing material while preventing direct plasma-substrate contact that would cause arc discharge and damage, thus resolving the contradiction between penetration capability and substrate protection
4Manufacturing precision
If additional flash steps are implemented to address clogging, then etching uniformity improves, but process complexity increases and throughput decreases
Solution Approach 1:
The invention extracts and eliminates the root cause of clogging by replacing silicon-containing mask materials with boron-and-nitrogen-containing materials. This material substitution removes the source of redeposition and clogging problems, making additional flash steps unnecessary and thereby reducing process complexity while maintaining etching uniformity
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 method reduces clogging and redeposition, enhances etching uniformity, and decreases the need for flash steps, thereby increasing throughput and maintaining high-quality feature formation in semiconductor processing.
Implementation Method 1
forming a plasma of the oxygen-containing precursor to produce oxygen-containing plasma effluents
Implementation Method 2
Chemical etching is used for a variety of purposes including transferring a pattern in photoresist into underlying layers
Implementation Method 3
forming a plasma of the fluorine-containing precursor to produce fluorine-containing plasma effluents
Implementation Method 4
etching oxidized portions of the boron-and-nitrogen-containing material, oxidized portions of the carbon-containing material, or both
Data Source
AI summary
Exemplary semiconductor processing methods may include providing an oxygen-containing precursor to a processing region of a semiconductor processing chamber. The methods may include forming a plasma of the oxygen-containing precursor to produce oxygen-containing plasma effluents. The methods may include contacting a substrate housed in the processing region with the oxygen-containing plasma effluents. The substrate may include a boron-and-nitrogen-containing material overlying a carbon-containing material. The boron-and-nitrogen-containing material comprises a plurality of openings. The methods may include etching the carbon-containing material.