Combined Gate-Contact Links for Uniform Grid IC Patterning
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Solution Overview
Problem
The challenge of maintaining mobility improvement and short channel control in multi-gate and nanowire transistors as device dimensions scale below the 10 nanometer node, particularly due to constraints on lithographic processes and trade-offs between feature dimensions and spacing, is addressed by integrating a uniform grid metal gate and trench contact cut structure.
Innovation Solution
A unified dielectric cut plug process is used to form a pixel structure with combined links for trench and gate contacts, eliminating separate patterning operations and reducing process complexity and variation, while ensuring seamless metal fill and improved robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If separate patterning operations are used for trench contact and gate contact, then manufacturing precision can be maintained for each feature, but device complexity and process variation increase
Solution Approach 1:
The patent combines separate patterning operations for trench contact and gate contact into a single unified patterning process. The uniform grid structure allows both contact types to be defined simultaneously, reducing the number of lithography steps from multiple separate operations to one integrated process, thereby simplifying device complexity while maintaining manufacturing precision through consistent single-step patterning
Solution Approach 2:
The uniform grid structure serves multiple functions: it defines both trench contact locations and gate contact locations within the same patterned layer. This multi-functional approach eliminates the need for separate patterning operations for different contact types, reducing process variation and simplifying the overall fabrication process while maintaining precision for both feature types
2Area of moving object
If feature dimensions are reduced to increase device density, then capacity increases, but lithographic process constraints worsen
Solution Approach 1:
The patent segments the contact structure into a uniform grid of identical repeating units, where each unit contains both trench contact and gate contact features. This segmentation into standardized modules allows for scalable fabrication at reduced dimensions, as the same lithographic pattern can be repeated across the wafer, simplifying the manufacturing process even as device density increases
Solution Approach 2:
The uniform grid approach changes the geometric parameters of the contact structure by establishing fixed, uniform spacing and dimensions for all contacts. This parameter standardization enables the lithographic process to operate at reduced feature sizes with consistent exposure and development conditions, making high-density fabrication more manageable despite the reduced feature dimensions
3Length of stationary object
If multiple separate patterning operations are used, then feature spacing can be optimized independently, but process variation increases
Solution Approach 1:
The patent merges the patterning of trench contacts and gate contacts into a single simultaneous operation using the uniform grid structure. Since both feature types are defined in one lithography step, their relative spacing is determined by the single pattern exposure, eliminating cumulative alignment errors from multiple steps and reducing overall process variation while maintaining optimized feature spacing
Data Source
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.