In-Situ ALD Protective Layer for ULK Etch Damage
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Solution Overview
Problem
Ultra-low dielectric (ULK) material layers in microelectronic devices are susceptible to damage during etch processing, leading to degraded electrical performance and reliability due to chamfer angle degradation and rounded corners, which are exacerbated at smaller pitches.
Innovation Solution
A protective layer, such as an oxide-containing SiO2 film deposited using atomic layer deposition (ALD), is applied in-situ within the etch chamber to shield ULK features from damage during etch processes, maintaining chamfer angles between 85° and 90° and preventing undesired rounding of corners.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If plasma etch processing is performed on ULK material layers, then trenches and vias can be formed in the patterned structure, but the ULK features become damaged with degraded chamfer angles and rounded corners
Solution Approach 1:
A protective layer is deposited over the ULK material layer before etch processing. This preliminary protective action prevents plasma damage to the ULK features during subsequent etching operations, maintaining chamfer angle precision and preventing material degradation.
Solution Approach 2:
The protective layer acts as an intermediary barrier between the plasma etch environment and the ULK material. This intermediate layer shields the sensitive ULK features from direct exposure to harmful plasma species while allowing the etch process to proceed on other layers.
2Reliability
If protective layers are deposited to shield ULK features, then ULK material integrity is preserved, but process complexity increases
Solution Approach 1:
The protective layer deposition is combined with the existing etch chamber workflow. The protective layer is deposited in-situ within the etch chamber, merging the protection function with the existing process equipment and reducing the need for additional separate processing steps.
Solution Approach 2:
The protective layer serves multiple functions: it protects ULK features from plasma damage, maintains chamfer angle precision, and can be selectively removed after etching. This multi-functionality reduces the need for separate protective measures and simplifies the overall process.
3Productivity
If in-situ deposition is used within the etch chamber, then process throughput is maintained, but deposition uniformity must be controlled
Solution Approach 1:
Deposition parameters such as temperature, pressure, and precursor flow rates are optimized and controlled during in-situ deposition within the etch chamber. These parameter changes ensure uniform protective layer formation while maintaining process throughput by avoiding additional 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 protective layer significantly reduces damage to ULK features, preserving the integrity of chamfer angles and preventing electrical shorts, thereby enhancing the reliability and performance of microelectronic devices without significantly impacting process throughput.
Implementation Method 1
an oxide-containing layer, such as a SiO2 film, is deposited using atomic layer deposition (ALD)
Data Source
AI summary
Embodiments are disclosed for processing microelectronic workpieces having patterned structures that include ultra-low dielectric constant (k) (ULK) material layers. In particular, embodiments are disclosed that deposit protective layers to protect ULK features during etch processing of patterned structures within substrates for microelectronic workpieces. For certain embodiments, these protective layers are deposited in-situ within the etch chamber.