Low-k Dielectric Layer Formation via Alternating Carbon Oxygen Deposition
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Solution Overview
Problem
High integration density and demand for high-speed semiconductor devices pose challenges in manufacturing, including reduced exposure process margins and difficulties in achieving improved etch resistance and electrical characteristics.
Innovation Solution
A method of forming a low-k layer using a silicon source, carbon source, oxygen source, and nitrogen source in a plasma-enhanced atomic layer deposition process, with alternating sub-cycles of carbon and oxygen source provision to increase carbon and oxygen composition, enhancing etch resistance and dielectric properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If high integration density is achieved, then device functionality is improved, but exposure process margin is reduced
Solution Approach 1:
The patent segments the deposition process into multiple alternating sub-cycles, each dedicated to depositing either carbon-containing material or oxygen-containing material. This segmentation allows precise control over the composition of the low-k layer, enabling high integration density while maintaining manufacturing precision through controlled material deposition sequences.
Solution Approach 2:
The patent changes the compositional parameters of the low-k layer by controlling the ratio and sequence of carbon and oxygen source deposition. By adjusting the carbon-to-oxygen ratio through alternating sub-cycles, the dielectric constant is optimized to achieve both high integration density and adequate exposure process margin.
2Strength
If carbon composition is increased, then etch resistance is improved, but dielectric constant may increase
Solution Approach 1:
The patent precisely controls the carbon composition parameter by adjusting the number and duration of carbon-source sub-cycles within the alternating deposition sequence. This allows optimization of etch resistance while maintaining the dielectric constant at 5.0 or less by balancing carbon deposition with subsequent oxygen deposition in alternating sub-cycles.
Solution Approach 2:
The patent creates a composite low-k layer structure by alternating deposition of carbon-containing materials and oxygen-containing materials. This composite structure achieves both high etch resistance (from carbon) and low dielectric constant (from oxygen), resolving the contradiction between these two properties.
3Reliability
If oxygen composition is increased, then dielectric constant is reduced, but etch resistance may decrease
Solution Approach 1:
The patent controls the oxygen composition parameter by adjusting the number and duration of oxygen-source sub-cycles in the alternating deposition sequence. This allows optimization of the dielectric constant while maintaining adequate etch resistance by balancing oxygen deposition with preceding carbon deposition in alternating sub-cycles.
Solution Approach 2:
The alternating deposition process creates a composite structure where carbon-rich layers provide etch resistance and oxygen-rich layers provide low dielectric constant. This composite material approach resolves the contradiction between improving dielectric constant and maintaining etch resistance.
4Productivity
If plasma enhancement is used, then deposition efficiency is improved, but process complexity increases
Solution Approach 1:
The patent employs periodic plasma enhancement in alternating sub-cycles, activating plasma only during carbon-source and oxygen-source deposition phases. This periodic application maintains high deposition efficiency while managing process complexity through a systematic, repeating pattern rather than continuous plasma operation.
Solution Approach 2:
The patent changes the plasma activation parameter selectively during different sub-cycles, applying plasma enhancement during deposition phases to improve efficiency while avoiding continuous plasma operation that would increase complexity. The plasma parameters are adjusted to match the specific requirements of carbon versus oxygen source deposition.
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 improves etch resistance and electrical characteristics of semiconductor devices by increasing carbon and oxygen composition in the low-k layer, achieving a dielectric constant of 5.0 or less, suitable for gate spacers and reducing parasitic capacitance.
Implementation Method 1
A method of forming a low-k layer using a silicon source, carbon source, oxygen source, and nitrogen source in a plasma-enhanced atomic layer deposition process
Data Source
AI summary
A method of forming a low-k layer includes forming a layer by providing a silicon source, a carbon source, an oxygen source, and a nitrogen source onto a substrate. The forming of the layer includes a plurality of main cycles, and each of the main cycles includes providing the silicon source, providing the carbon source, providing the oxygen source, and providing the nitrogen source, each of which is performed at least one time. Each of the main cycles includes sub-cycles in which the providing of the carbon source and the providing of the oxygen source are alternately performed.