FinFET Fin Structural Support via Dummy Elements and Silicon Compounds
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Solution Overview
Problem
Minimizing the dimensions of fin structures in FinFETs to prevent collapse and ensure proper functionality during fabrication, as reduced dimensions can lead to undesired removal of fins, affecting the device's performance.
Innovation Solution
Applying a silicon compound such as SiGe or SiC adjacent to the channel region to provide structural support and enhance carrier mobility by applying compressive or tensile stress, and using a method involving a mask, dummy elements, and specific etching processes to maintain the fin structure during manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the dimensions of the fin are minimized, then the FinFET size is reduced, but the fin may collapse and be undesirably removed during fabrication
Solution Approach 1:
A dummy element is formed over a portion of the mask before the etching process to provide preliminary structural support to the fin. This dummy element prevents the fin from collapsing during subsequent fabrication steps, allowing the fin to maintain its minimized dimensions while ensuring structural integrity throughout the manufacturing process
Solution Approach 2:
The dummy element acts as an intermediary structural component between the mask and the fin. It provides mechanical support to the minimized fin structure during fabrication without interfering with the final device functionality, as the dummy element is later removed after serving its protective purpose
2Reliability
If a dummy element is used to support the fin, then the fin structural integrity is improved, but the device complexity increases
Solution Approach 1:
The dummy element formation is merged with existing fabrication steps by using the same mask and etching processes already required for fin formation. The dummy element is created as part of the same patterning sequence, combining multiple functions into a unified process flow that minimizes additional complexity
Solution Approach 2:
The dummy element is designed as a temporary structure that is discarded after serving its protective function. It is removed in a subsequent cleaning step after the fin has been successfully formed and stabilized, allowing the temporary complexity to be eliminated from the final device
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
The silicon compound supports the fin elements, preventing collapse and enhancing carrier mobility, thereby improving the yield and performance of FinFETs by maintaining the structural integrity and functionality of the semiconductor devices.
Implementation Method 1
A silicon compound (e.g., SiGe or SiC) may be disposed adjacent to a channel region of a semiconductor device (e.g., a FinFET) to apply stress on the channel region. Compressive stress or tensile stress in the channel region can improve the mobility of the hole or electron.
Data Source
AI summary
A semiconductor device manufacturing method includes providing a mask on a semiconductor member. The method further includes providing a dummy element to cover a portion of the mask that overlaps a first portion of the semiconductor member and to cover a second portion of the semiconductor member. The method further includes removing a third portion of the semiconductor member, which has not been covered by the mask or the dummy element. The method further includes providing a silicon compound that contacts the first portion of the semiconductor member. The method further includes removing the dummy element to expose and to remove the second portion of the semiconductor member. The method further includes forming a gate structure that overlaps the first portion of the semiconductor member. The first portion of the semiconductor member is used as a channel region and is supported by the silicon compound.