Fin Structure Cutting With Dielectric Mold Etch Stop
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Solution Overview
Problem
In the semiconductor industry, fabricating non-planar transistor devices such as FinFETs and GAA transistors is challenging due to the risk of damaging neighboring fin structures during the cutting process, which affects the overall performance of integrated circuits, especially when fin structures are closely spaced.
Innovation Solution
A method is introduced where a dielectric mold is formed between adjacent fin structures to serve as an etch stop layer, allowing for more accurate and reliable cutting of fin structures, even when they are closely spaced, by using the mold to protect uncut fin structures and enabling the formation of shallow trench isolation regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fin structures are closely spaced to increase integration density, then the number of transistors per area increases, but the risk of damaging neighboring fin structures during cutting increases
Solution Approach 1:
A dielectric mold is introduced as an intermediary structure positioned between adjacent fin structures. This mold serves as a physical barrier and etch stop layer that prevents damage to neighboring fins during the cutting process, enabling closer spacing of fins while maintaining reliability.
Solution Approach 2:
The dielectric mold is formed between the fin structures before the cutting process is performed. This preliminary action of placing the protective mold allows subsequent cutting operations to proceed safely with enhanced process window, as the protective structure is already in place to prevent damage.
2Manufacturing precision
If a dielectric mold is formed between fin structures to protect them during cutting, then cutting accuracy and reliability improve, but device complexity increases
Solution Approach 1:
The dielectric mold serves as a temporary protective structure that is discarded after fulfilling its protective function during cutting. The mold is removed in a subsequent step, allowing the finished device to maintain its original structural complexity without the additional mold elements.
3Reliability
If the dielectric mold is used as an etch stop layer to protect uncut fin structures, then the process window for cutting is enlarged, but the manufacturing process becomes more complex
Solution Approach 1:
The dielectric mold is introduced as a temporary process element that provides critical protection during cutting operations, then is discarded in a subsequent removal step. This allows the process window to be enlarged without permanently increasing the complexity of the final device structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enlarges the process window for cutting fin structures, enhancing the accuracy and reliability of fabricating integrated circuits with a large number of transistors by protecting uncut fin structures and allowing for more precise control during the etching process.
Implementation Method 1
forming a mold by filling up trenches between neighboring ones of the first through third fin structures with a first dielectric material... allowing for more accurate and reliable cutting of fin structures, even when they are closely spaced, by using the mold to protect uncut fin structures
Data Source
AI summary
A method for making a semiconductor device includes forming a first fin structure, a second fin structure, and a third fin structure over a substrate. The first through third fin structures all extend along a first lateral direction, and the second fin structure is disposed between the first and third fin structures. The method includes forming a mold by filling up trenches between neighboring ones of the first through third fin structures with a first dielectric material. The method includes cutting the second fin structure by removing an upper portion of the second fin structure. The method includes replacing the upper portion of the second fin structure with a second dielectric material to form a dielectric cut structure. The method includes recessing the mold to expose upper portions of the first fin structure and the third fin structure, respectively.