Trench Bottom Modified Layer for Semiconductor Interconnects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The mechanical strength of insulating films with low dielectric constants in semiconductor devices is insufficient, leading to the formation of sub-trenches during the process of forming barrier and seed metals, which increases interconnect capacitance and reduces the reliability of semiconductor devices.
Innovation Solution
A semiconductor device is developed using an insulating film formed with cyclic siloxane having a six-membered ring structure, where a modified layer with a higher concentration of carbon and/or nitrogen atoms is formed on the trench bottom surface using plasma treatment, enhancing mechanical strength and preventing sub-trench formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a low dielectric constant insulating film is used to reduce inter-interconnect capacitance, then the inter-interconnect capacitance is reduced, but the mechanical strength of the insulating film becomes insufficient
Solution Approach 1:
The patent applies local quality by forming a modified layer with different composition (higher carbon and/or nitrogen content) specifically at the trench bottom surface, while the bulk insulating film maintains its low dielectric constant properties. This localized modification provides enhanced mechanical strength and resistance to sputtering damage only where needed, without compromising the overall low capacitance特性 of the insulating film.
Solution Approach 2:
The patent creates a composite structure consisting of the low dielectric constant insulating film (such as porous SiOCH) combined with a modified layer containing higher concentrations of carbon and/or nitrogen atoms. This composite structure integrates the low capacitance advantage of the porous insulating film with the mechanical strength and sputtering resistance of the carbon/nitrogen-rich modified layer.
2Ease of manufacture
If barrier metal and seed metal are formed by repeating sputtering and etching processes, then the interconnect structure is formed, but sub-trench is generated at the bottom surface of the trench due to insufficient mechanical strength
Solution Approach 1:
The patent applies preliminary action by forming the modified layer with enhanced mechanical strength and sputtering resistance on the trench bottom surface before performing the barrier metal and seed metal formation processes. This pre-prepared modified layer prevents sub-trench generation during subsequent sputtering and etching operations, ensuring trench shape precision is maintained throughout the interconnect formation process.
3Loss of energy
If the insulating film has low mechanical strength, then the dielectric constant can be reduced, but cracks or peeling may occur during manufacturing processes with large stress
Solution Approach 1:
The patent applies local quality by concentrating the mechanical reinforcement in the modified layer at the trench bottom surface, where stress concentration and damage are most likely to occur during manufacturing processes. The bulk insulating film retains its low dielectric constant structure, while the localized modified layer provides the necessary mechanical strength to prevent cracks and peeling under stress.
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 modified layer with increased carbon and nitrogen atoms improves the mechanical strength, preventing sub-trench formation and reducing effective interconnect capacitance, thereby enhancing the reliability and performance of semiconductor devices.
Implementation Method 1
forming a modified layer on a bottom surface of the trench by treating the bottom surface of the trench with plasma generated from a carbon-containing gas, a nitrogen-containing gas, or a mixed gas thereof
Data Source
AI summary
The semiconductor device includes an insulating film that is formed using a cyclic siloxane having a six-membered ring structure as a raw material; a trench that is formed in the insulating film; and a interconnect that is configured by a metal film embedded in the trench. In the semiconductor device, a modified layer is formed on a bottom surface of the trench, in which the number of carbon atoms and/or the number of nitrogen atoms per unit volume is larger than that inside the insulating film.