Capacitor Sealing Liner Prevents ULK Precursor Infiltration
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Solution Overview
Problem
In ultra-high density integrated circuits, the use of ultra-low-k (ULK) dielectric materials, while improving signal-to-noise ratio and reducing crosstalk, poses challenges due to their porosity, leading to issues like precursor infiltration, conductive path creation, and increased dielectric constant, which can result in reduced device performance and potential failure.
Innovation Solution
A method involving the formation of a sealing liner with a material having openings smaller than the precursor particle size, using anisotropic etching to create the liner, and depositing a first metal layer within the capacitor opening using a precursor with a minimum particle size, thereby preventing precursor infiltration and maintaining low dielectric constant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ULK dielectric materials are used to reduce crosstalk and improve signal-to-noise ratio, then the signal quality is improved, but the porosity of the material increases leading to precursor infiltration and device failure
Solution Approach 1:
A seal liner layer is introduced as an intermediary barrier between the porous ULK dielectric material and the capacitor opening. This seal liner prevents precursor material from infiltrating into the porous ULK material during capacitor electrode formation, while allowing the ULK material to maintain its low-k properties for reduced crosstalk. The seal liner acts as a mediator that blocks harmful precursor infiltration paths.
Solution Approach 2:
The dielectric structure is segmented into multiple functional layers: the porous ULK dielectric material layer for crosstalk reduction, and a separate seal liner layer for preventing precursor infiltration. This segmentation allows each layer to perform its specific function independently, resolving the contradiction between porosity benefits and infiltration risks.
2Reliability
If the capacitor opening is formed in porous ULK material, then the dielectric constant is reduced for better signal performance, but conductive paths may form leading to short circuits
Solution Approach 1:
The seal liner serves as a protective intermediary layer lining the capacitor opening in the porous ULK material. It prevents conductive precursor material from creating unwanted conductive paths within the porous structure, while allowing the ULK material to maintain its low dielectric constant for optimal signal performance.
Solution Approach 2:
The seal liner is formed in advance before capacitor electrode deposition to preemptively block potential conductive path formation. By establishing this protective barrier beforehand, the patent prevents the harmful effect of precursor infiltration and conductive path creation before it can occur during subsequent processing steps.
3Speed
If feature sizes are decreased to enhance transistor performance, then the drive current and switching speed are improved, but the cross-sectional area of contact elements is reduced increasing electrical resistance
Solution Approach 1:
The patent employs copper metallization (a superior conductor) in combination with the sealed capacitor structure to compensate for the increased electrical resistance in scaled contact elements. The composite approach of using high-conductivity copper interconnects alongside the sealed capacitor design helps maintain low overall resistance despite reduced contact element dimensions.
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
This approach reduces the risk of short circuits and maintains the low dielectric constant of ULK materials, enhancing the reliability and performance of capacitors in semiconductor devices.
Implementation Method 1
performing an anisotropic etching process to thereby form a sealing liner on the sidewalls of the capacitor opening
Implementation Method 2
forming a first metal layer in the capacitor opening and on the sealing liner by performing a process using a precursor having a minimum particle size
Data Source
AI summary
Generally, the subject matter disclosed herein relates to various methods of making a capacitor with a sealing liner and a semiconductor device including such a capacitor. In one example, the method includes forming a layer of insulating material, forming a capacitor opening in the layer of insulating material, forming a sealing liner on the sidewalls of the capacitor opening and forming a first metal layer in the capacitor opening and on the sealing liner by performing a process using a precursor having a minimum particle size, wherein the sealing liner is made of a material having an opening size that is less than the minimum particle size of the precursor.