GAA Semiconductor Dielectric Wall Formation in Narrow Fin Trenches
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Solution Overview
Problem
The integration of gate-all-around (GAA) transistor devices in semiconductor manufacturing is challenging due to difficulties in forming dielectric walls at specific locations as trenches become increasingly smaller, affecting manufacturing yield.
Innovation Solution
A method is employed to form a dielectric liner in a first trench using a patterning process, where the dimension of the remaining portion is less than that of a second trench, allowing the dielectric wall to be selectively formed, thereby overcoming the challenge of forming dielectric walls in smaller trenches and improving manufacturing yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods are used to form dielectric walls in trenches, then manufacturing process is simpler, but manufacturing precision deteriorates as trenches become smaller
Solution Approach 1:
The patent divides the trench structure into multiple segments by forming dielectric walls at specific locations within the trench. This segmentation allows precise control of dielectric material placement, enabling high manufacturing precision in small trenches while managing process complexity through systematic division of the formation process into discrete steps.
Solution Approach 2:
The patent employs preliminary patterning actions to define trench dimensions and dielectric wall locations before actual dielectric material deposition. This preliminary structuring enables subsequent precise formation of dielectric walls in miniaturized trenches, resolving the contradiction between precision requirements and process complexity.
2Reliability
If multi-gate devices are introduced to improve gate control, then device performance is improved, but integration of fabrication becomes more challenging
Solution Approach 1:
The patent implements gate-all-around structures that completely surround the channel region, with dielectric walls nested within trenches at specific locations. This nested configuration provides superior gate control by enclosing the channel from multiple directions while maintaining fabrication feasibility through systematic process integration.
Solution Approach 2:
The patent applies different dielectric materials and structural configurations at different locations within the device - specifically forming dielectric walls at select trench locations while leaving other regions open for gate structures. This local differentiation optimizes gate control in critical areas while simplifying fabrication in other regions, resolving the contradiction between performance and manufacturability.
3Productivity
If trenches are scaled down to increase device density, then productivity is improved, but manufacturing precision deteriorates
Solution Approach 1:
The patent introduces intermediary patterning steps and dielectric liner structures that mediate between the scaled-down trench dimensions and the required dielectric wall precision. These intermediary elements enable precise dielectric material placement even in miniaturized trenches, allowing high device density while maintaining manufacturing precision through systematic process design.
Data Source
AI summary
A method for forming a semiconductor structure is provided. The method includes forming first, second and third fin structures over a substrate, forming a first dielectric material along a first trench between the first fin structure and the second fin structure and along a second trench between the second fin structure and the third fin structure, removing a first portion of the first dielectric material along the second trench while leaving a second portion of the first dielectric material along the first trench as a dielectric liner, depositing a second dielectric material over the dielectric liner and filling the first trench and the second trench, and etching back the second dielectric material until the dielectric liner is exposed. A first portion of the second dielectric material remaining in the first trench forms a dielectric wall.