Combined Gate and Trench Contact Links for Tight IC Grid Spacing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge of maintaining mobility improvement and short channel control in microelectronic devices as device dimensions scale below the 10 nanometer node, particularly in multi-gate and nanowire transistors, is exacerbated by the constraints on lithographic processes used to pattern features, leading to a trade-off between critical dimension and spacing.
Innovation Solution
The integration of a unified dielectric cut plug structure for both trench contacts and gate cuts, allowing for a simplified process that combines gate contact and trench contact links, reducing process complexity and variation, and enabling self-aligned removal of plugs, thereby improving robustness and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional separate processes are used for trench contacts and gate cuts, then manufacturing precision can be maintained, but device complexity and process variation increase
Solution Approach 1:
The patent combines the trench contact link and gate link formation into a single unified process step, where both links are formed simultaneously in the same lithographic and deposition cycle. This merging eliminates the need for separate patterning and deposition operations for each link type, reducing process complexity while maintaining alignment precision through self-aligned formation.
Solution Approach 2:
The unified dielectric cut plug structure serves multiple functions: it acts as both the trench contact link and the gate link, and also provides the dielectric material for electrical isolation. This multi-functional structure eliminates the need for separate link structures and reduces the overall number of process steps required.
2Area of moving object
If tight spacing is maintained for scaled devices, then device density increases, but lithographic process constraints are exacerbated
Solution Approach 1:
The dielectric cut plugs are formed preliminarily during the same deposition process as the metal gate and trench contact fills, before subsequent processing steps. This preliminary formation of both links and dielectric plugs in a single operation enables tight spacing to be achieved without requiring additional lithographic steps that would be constrained by scaling limits.
Solution Approach 2:
The patent transitions from planar link formation to a three-dimensional structure where dielectric cut plugs extend vertically through multiple layers. This dimensional change allows the links to be formed at different vertical levels, enabling tight horizontal spacing while maintaining electrical isolation and functionality.
3Manufacturing precision
If separate patterning operations are used for gate contact links and trench contact links, then manufacturing precision can be maintained, but productivity decreases
Solution Approach 1:
Both gate contact links and trench contact links are formed in a single unified patterning and deposition operation, eliminating the need for separate lithographic exposures and deposition cycles. This merging of operations maintains alignment precision through self-aligned formation while significantly improving process throughput by reducing the total number of process steps.
Solution Approach 2:
The unified process enables continuous formation of both link types without interruption or repositioning of the substrate between operations. The single deposition process continuously fills both gate and trench contact regions simultaneously, maximizing productivity while maintaining precision through the continuous nature of the process.
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
Integrated circuit structures having combined links for uniform grid metal gate and trench contact cut are described. A structure includes a dielectric sidewall spacer between a gate electrode and a conductive trench contact. First and second parallel dielectric cut plug structures extend through the gate electrode, through the dielectric sidewall spacer, and through the conductive trench contact. The first dielectric cut plug has a first recess laterally adjacent to first and second portions of the gate electrode. The second dielectric cut plug has a second recess laterally adjacent to first and second portions of the conductive trench contact. A conductive link is in the first recess, in the second recess, and continuous between the first recess and the second recess.