Self-Formed Barrier Film for Copper Interconnect Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor device manufacturing, the formation of a self-formed barrier film is inadequate, leading to poor adhesion between the conductive layer and the interlayer insulating films, causing the conductive layer to separate during thermal treatment and CMP processes, especially when a high concentration of Mn is used in the alloy layer, increasing wiring resistance and burdening the plating process.
Innovation Solution
A method involving the formation of a porous or modified insulating film on the substrate's inner walls, followed by a copper alloy layer, where thermal treatment promotes the formation of a self-formed barrier film with copper diffusion barrier properties, enhancing adhesion and preventing conductive layer separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a self-formed barrier film is formed by thermal treatment of Mn-containing alloy layer, then wiring resistance is reduced and adhesion is improved, but the barrier film formation is inadequate causing conductive layer separation
Solution Approach 1:
The patent applies preliminary action by forming a porous layer in the insulating film before depositing the Mn-containing alloy layer. This porous structure is prepared in advance to facilitate subsequent barrier film formation during thermal treatment, ensuring adequate adhesion without requiring high Mn concentrations that would increase wiring resistance.
Solution Approach 2:
The patent utilizes porous materials by creating a porous layer within the insulating film through plasma treatment or other methods. This porous structure increases the surface area and reactivity at the interface, enabling effective barrier film formation with lower Mn concentrations, thus resolving the contradiction between adhesion quality and wiring resistance.
2Reliability
If high concentration of Mn is used in alloy layer to improve barrier film formation, then adhesion is enhanced, but wiring resistance increases and plating process is burdened
Solution Approach 1:
The patent applies local quality by concentrating Mn content specifically at the interface region between the alloy layer and insulating film, rather than uniformly distributing high Mn concentration throughout the entire alloy layer. This localized enrichment provides sufficient barrier film formation and adhesion enhancement while maintaining low overall wiring resistance.
Solution Approach 2:
The porous layer structure enables efficient Mn diffusion and barrier film formation with reduced Mn quantities. The increased surface area and porosity facilitate reactive sites for barrier film formation, allowing adequate adhesion with lower Mn concentrations compared to dense insulating film structures.
3Reliability
If conventional barrier film formation is used, then Cu diffusion prevention is achieved, but wiring pitch scaling becomes difficult and manufacturing complexity increases
Solution Approach 1:
The patent applies self-service by enabling the barrier film to form automatically through thermal treatment of the Mn-containing alloy layer in contact with the porous insulating film. This self-formed barrier film eliminates the need for separate barrier film deposition processes, simplifying manufacturing while maintaining effective Cu diffusion prevention.
Solution Approach 2:
The patent utilizes parameter changes by controlling the thermal treatment conditions (temperature, time, atmosphere) to optimize barrier film formation. By adjusting these parameters, the barrier film forms with appropriate thickness and quality, achieving Cu diffusion prevention without complex additional process 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 method facilitates the formation of a continuous self-formed barrier film at the interface, improving adhesion and preventing conductive layer separation, thereby enhancing the yield and reliability of semiconductor devices.
Implementation Method 1
thermal treatment is effected to enable the metal in the alloy layer to react with a constituent component of the insulating film, thereby forming a self-formed barrier film
Implementation Method 2
thermal treatment is effected to enable the metal in the alloy layer to react with a constituent component of the insulating film, thereby forming a self-formed barrier film made of a metal compound
Data Source
AI summary
A method for manufacturing a semiconductor device includes: the first step of forming, in an insulating film provided on a substrate, a recess that is porositized at least at inner walls; the second step of forming an alloy layer made of copper and a metal other than copper so as to cover the inner walls of the recess; the third step of burying a conductive layer made primarily of copper in the recess provided with the alloy layer; the fourth step of subjecting the thus treated substrate to thermal treatment to cause the metal in the alloy layer to react with a constituent component of the insulating film to form a barrier film made of a metal compound having Cu diffusion barrier properties.