Gate-All-Around Transistor Spacer Structure for Self-Aligned Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The semiconductor integrated circuit (IC) industry faces challenges in processing and manufacturing complex ICs due to the scaling down process, which increases complexity and requires improved manufacturing methods.
Innovation Solution
The formation of a semiconductor device structure involving a stack of semiconductor layers with alternating materials and nanostructure channels, utilizing multi-patterning and self-aligned processes to create gate-all-around transistors, including the use of sacrificial gate structures and dielectric spacers to define channel regions, enhances manufacturing efficiency and reduces electrical short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the scaling down process is used to increase functional density, then the number of interconnected devices per chip area increases, but the complexity of processing and manufacturing ICs increases
Solution Approach 1:
The patent divides the gate formation process into multiple discrete steps: forming sacrificial gates, depositing first spacers, forming openings, depositing second spacers, and removing sacrificial gates. This segmentation allows each step to be optimized independently, managing the complexity of creating gate-all-around structures at scaled dimensions while achieving high functional density through precise control of each segmentation step
Solution Approach 2:
The patent employs preliminary actions by forming sacrificial gate structures before the actual gate electrodes, and using dielectric spacers to preDefine channel regions and isolate adjacent structures. These preliminary structures guide subsequent processing steps and prevent defects, reducing overall manufacturing complexity despite the scaled-down dimensions requiring high precision
2Manufacturing precision
If multi-patterning and self-aligned processes are used to create gate-all-around transistors, then manufacturing precision improves, but device complexity increases
Solution Approach 1:
The patent implements self-aligned processes where dielectric spacers automatically form at precise locations relative to sacrificial gates and channel structures, and subsequent openings are self-aligned to the spacer structures. This self-alignment mechanism eliminates the need for additional alignment steps, achieving high manufacturing precision for gate-all-around structures without proportionally increasing process complexity
Solution Approach 2:
The patent uses dielectric spacers as intermediary structures that mediate between the sacrificial gates and the final gate electrodes. These spacers serve multiple functions: defining channel regions, isolating adjacent structures, and providing alignment references for subsequent steps. The intermediary spacers simplify the overall process by consolidating multiple functions into a single structure type, managing device complexity while achieving high precision
3Reliability
If dielectric spacers are used to define channel regions and isolate adjacent structures, then electrical short circuits are reduced, but manufacturing steps increase
Solution Approach 1:
The patent designs dielectric spacers to perform multiple functions simultaneously: defining channel regions, isolating adjacent structures to prevent electrical shorts, and providing alignment references for subsequent gate electrode formation. By consolidating these functions into a single structure type formed through integrated steps, the patent achieves high electrical reliability without adding excessive manufacturing complexity, as the same spacer structures serve all three purposes
Data Source
AI summary
Embodiments of the present disclosure provide a semiconductor device structure and methods of forming the same. The structure includes a substrate portion extending from a substrate, a semiconductor layer disposed over the substrate portion, a gate structure surrounding at least a portion of the semiconductor layer, and first and second dielectric spacers disposed on the semiconductor layer. A portion of the gate structure is disposed between the first and second dielectric spacers, and each of the first and second dielectric spacer includes a first spacer layer and a second spacer layer disposed adjacent the first spacer layer. The second spacer layer has an outer edge and an inner edge, and a length of the outer edge is substantially greater than a length of the inner edge.