Fin Pattern Segmentation With Spacing Layers for Fin Cut Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The process window for fin cut processes in semiconductor manufacturing is shrinking, leading to increased difficulty in forming fins with desired spacing and maintaining uniformity and accuracy in pattern layers, particularly in FinFET structures, due to challenges in etching and removing dummy fins.
Innovation Solution
A semiconductor structure forming method that involves forming boundary defining grooves and spacing layers to separate initial pattern layers, using these layers as stop positions during etching, enabling self-aligned etching along lateral and longitudinal directions to enhance process windows and control critical dimensions and profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional fin cut processes are used to form fins with desired spacing, then fin spacing can be achieved, but the process window is shrinking and manufacturing precision is deteriorating
Solution Approach 1:
The patent divides the continuous initial pattern layer into discrete segments by forming spacing layers in grooves between adjacent initial pattern layers. This segmentation allows independent control of each fin structure, enabling precise spacing adjustment without affecting the entire pattern layer, thus improving fin spacing precision while maintaining process window.
Solution Approach 2:
The patent performs preliminary actions by forming grooves and filling them with spacing layers before the final fin formation step. This preliminary structuring establishes precise spatial relationships and stop positions in advance, allowing the subsequent etching process to proceed with larger process margins and improved manufacturing precision.
2Manufacturing precision
If dummy fins are removed to meet design requirements, then pattern accuracy is improved, but etching control becomes more difficult and manufacturing precision deteriorates
Solution Approach 1:
The patent introduces spacing layers as intermediary structures between the initial pattern layers and the final fin structures. These spacing layers serve as mediators that simplify etching control by providing uniform stop positions and protecting dummy fins during selective removal, thereby maintaining pattern accuracy while reducing etching control complexity.
Solution Approach 2:
The patent applies different treatments to different regions: spacing layers are formed in grooves between initial pattern layers in target areas, while dummy fin regions receive different processing. This local differentiation enables precise pattern accuracy control in active areas while simplifying the overall etching process through standardized structures.
3Ease of manufacture
If self-aligned etching is implemented using spacing layers as stop positions, then process window is enlarged, but device complexity increases
Solution Approach 1:
The spacing layers serve multiple functions simultaneously: they act as stop positions for self-aligned etching, provide mechanical support for initial pattern layers, define fin spacing, and protect underlying structures during processing. This multi-functionality enlarges the process window while avoiding additional complex structures.
Solution Approach 2:
The patent merges the spacing definition function and the etching stop function into a single spacing layer structure. By combining these functions, the process window is enlarged as fewer separate structures are needed, and the overall device complexity is managed through integrated design rather than multiple independent components.
Data Source
AI summary
Semiconductor structures and forming methods are disclosed. One form of a method includes: forming mask spacers on a base; patterning a target layer using the mask spacers as masks, to form discrete initial pattern layers, where the initial pattern layers extend along a lateral direction and grooves are formed between a longitudinal adjacent initial pattern layers; forming boundary defining grooves that penetrate through the initial pattern layers located at boundary positions of the target areas and cutting areas along the lateral direction; forming spacing layers filled into the grooves and the boundary defining grooves; and using the spacing layers located in boundary defining grooves and the spacing layers located in the grooves as stop layers along the lateral and the longitudinal directions respectively, etching the initial pattern layers located in the cutting areas, and using the remaining initial pattern layers located in the target areas as the target pattern layers.