Nickel Silicide Interconnects for Ultra-Fine Semiconductor Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor manufacturing techniques face challenges in forming interconnect patterns with line widths of 10 nanometers or less, as materials like copper and tungsten suffer from increased wire resistance due to electron scattering and poor adhesion, making it difficult to achieve stable and low-resistance interconnects.
Innovation Solution
The method involves forming amorphous silicon coatings on support elements, followed by siliciding to create nickel silicide interconnects, which reduces resistance and enhances adhesion, allowing for the formation of stable, low-resistance interconnects with line widths as small as 5 nanometers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If copper or tungsten is used for interconnect patterns with line widths of 10 nanometers or less, then the interconnect can be formed, but wire resistance increases due to electron scattering and adhesion problems occur
Solution Approach 1:
The patent changes the material parameter from conventional metals (copper, tungsten) to nickel silicide, and changes the formation method parameter from metal RIE to siliciding process. This parameter change resolves the contradiction by achieving low resistance (comparable to or lower than copper) and excellent adhesion while maintaining ultra-fine line widths of 10 nm or less
Solution Approach 2:
The patent uses a composite approach by forming nickel silicide through the reaction of nickel metal with silicon. This composite material (nickel silicide) combines the low resistance properties of metals with the adhesion benefits of silicon, resolving the contradiction between low wire resistance and good adhesion at ultra-fine dimensions
2Manufacturing precision
If copper or tungsten is used for interconnect patterns, then the interconnect can be formed, but adhesion problems occur
Solution Approach 1:
The patent introduces silicon as an intermediary material that reacts with nickel to form nickel silicide. This intermediary approach resolves the adhesion problem by creating a material that inherently bonds well to silicon-based semiconductor structures, eliminating the adhesion issues experienced with conventional metals like copper and tungsten
Solution Approach 2:
The patent changes the material parameter from pure metals (copper, tungsten) to a metal silicide compound (nickel silicide). This parameter change resolves the adhesion contradiction by providing excellent adhesion to silicon substrates and interlayer insulating films while maintaining ultra-fine line width capability
3Quantity of substance
If miniaturized patterns are formed to increase capacity, then higher capacity is achieved, but resistance increases due to electron scattering
Solution Approach 1:
The patent changes the material parameter to nickel silicide, which has superior electrical properties at ultra-fine dimensions. This parameter change resolves the contradiction by maintaining low resistance even when line widths are reduced to 10 nm or less, enabling higher device capacity without the resistance penalty that would normally accompany miniaturization
4Reliability
If nickel silicide is formed through siliciding process, then resistance is reduced and adhesion is enhanced, but additional process steps are required
Solution Approach 1:
The patent merges the interconnect formation process with the siliciding process. By depositing nickel metal and then performing a siliciding heat treatment, the process combines material deposition with chemical reaction to directly form the low-resistance nickel silicide interconnect. This merging approach resolves the contradiction by achieving superior electrical properties without adding excessive process complexity
Solution Approach 2:
The patent performs preliminary nickel metal deposition before the siliciding reaction. This preliminary action prepares the structure for the subsequent heat treatment that will transform the nickel into low-resistance nickel silicide. The preliminary deposition step enables the final siliciding process to produce the desired low-resistance interconnect with good adhesion
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 enables the formation of interconnects with significantly reduced resistance and improved stability, even at miniaturized sizes, by avoiding metal RIE processes and utilizing nickel silicide's strong immunity to resistance increases, thus facilitating high-density, ultra-fine semiconductor devices.
Implementation Method 1
forming a coating of amorphous silicon on the side face of the first support element
Implementation Method 2
siliciding the amorphous silicon of the coating to form an interconnect
Data Source
AI summary
A semiconductor device is manufactured by forming, on an insulating base material, a first support element having a side face that extends from a surface of the insulating base material, forming a coating of amorphous silicon on the side face of the first support element, filling an aperture disposed between the first support element and a second support element that extends from a surface of the insulating base material with an insulating film, planarizing the insulating film to expose an exposed portion of the coating and a surface of the first support element, and siliciding the amorphous silicon of the coating to form an interconnect.