Self-aligned gate cut structures for semiconductor devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lithography techniques struggle to achieve precise alignment of gate cut structures in semiconductor devices, leading to alignment errors and variations in gate material distribution, which can cause timing errors and device failures.
Innovation Solution
The formation of self-aligned gate cut structures using spacer structures and sacrificial materials, where the gate cut material is deposited between adjacent semiconductor devices, ensuring consistent distance and width across the integrated circuit, independent of traditional lithography alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional lithography techniques are used to align gate cut structures, then the manufacturing process is simple, but the alignment precision deteriorates leading to errors greater than 1.5 nm
Solution Approach 1:
The method performs preliminary actions by forming spacer structures on semiconductor fins before depositing the gate layer. These spacers serve as pre-positioned reference structures that define the exact location where gate cuts will later be made, ensuring precise alignment without relying on lithography. The sacrificial material is also preliminarily deposited in the regions between spacers, creating a ready-to-remove template for gate cut formation.
Solution Approach 2:
The invention introduces intermediary structures (spacers and sacrificial material) that mediate between the semiconductor fins and the final gate cut structures. The spacers act as intermediaries that transfer the positional information from the fins to the gate cut locations, while the sacrificial material serves as an intermediary template that is removed to create the gate cut openings. This intermediary approach eliminates direct lithography alignment requirements.
2Stability of the object's composition
If lithography alignment is used, then the process is straightforward, but gate material distribution becomes inconsistent causing timing errors
Solution Approach 1:
The spacer structures perform self-service by automatically defining the gate cut locations based on their own geometry and position relative to the semiconductor fins. The spacers self-align to the fins through conformal deposition, and their removal selectively creates gate cuts at precisely the right locations. This self-service mechanism ensures consistent gate material distribution without requiring external lithography alignment, thereby improving both composition stability and device reliability.
3Adaptability or versatility
If fixed gate cut width is used across all devices, then manufacturing is simpler, but adaptability to varying device proximity is lost
Solution Approach 1:
The invention applies local quality by allowing the gate cut width to vary locally based on the specific spacing between adjacent semiconductor fins at each location. The spacer structures are formed conformally on each fin, so the distance between spacers (and thus the gate cut width) automatically adapts to the local fin spacing. This local adaptation maintains manufacturing simplicity while achieving the versatility needed for different device proximities.
Data Source
AI summary
Techniques are provided herein to form semiconductor devices having self-aligned gate cut structures. In an example, neighboring semiconductor devices each include a semiconductor region extending between a source region and a drain region, and a gate layer extending over the semiconductor regions of the neighboring semiconductor devices. A gate cut structure that includes a dielectric material interrupts the gate layer between the neighboring semiconductor devices. Due to the process of forming the gate cut structure, the distance between the gate cut structure and the semiconductor region of one of the neighboring semiconductor devices is substantially the same as (e.g., within 1.5 nm of) the distance between the gate cut structure and the semiconductor region of the other one of the neighboring semiconductor devices.