Plasma Etching of Metal Gate Films With Directional Selectivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing plasma etching methods for GAA-FETs struggle to selectively remove metal-containing layers in complex and highly integrated semiconductor devices, particularly the metal gate film in specific directions, necessitating improved controllability for stable structure formation.
Innovation Solution
A plasma processing method that utilizes radical etching to remove a carbon-containing layer followed by selective removal of metal-containing layers using reactive ion etching, allowing precise control over the direction of metal gate film removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional plasma etching methods are used to remove metal-containing layers in GAA-FET processing, then the etching process can be performed, but selective removal of metal gate film in specific directions cannot be achieved and overetching occurs
Solution Approach 1:
The plasma etching process is segmented into two distinct stages: (1) a first plasma treatment stage that performs selective etching of the metal-containing layer in a first direction using a first gas mixture, and (2) a second plasma treatment stage that performs selective etching in a second direction perpendicular to the first direction using a second gas mixture. This segmentation allows precise directional control over metal gate film removal while preventing overetching, thereby improving manufacturing precision and structure stability.
2Shape
If isotropic processing is performed for nanowire or nanosheet formation, then the desired structure can be created, but control over the direction of metal gate film removal is lost
Solution Approach 1:
The invention applies different plasma treatment conditions to different spatial orientations of the metal-containing layer. The first plasma treatment selectively etches surfaces in the first direction, while the second plasma treatment selectively etches surfaces in the second direction perpendicular to the first direction. This local quality approach enables precise directional control over metal gate film removal while maintaining the desired nanowire or nanosheet structure formation.
3Ease of manufacture
If a single plasma gas mixture is used for etching, then the process is simple, but selective etching in different directions cannot be achieved
Solution Approach 1:
The invention dynamically adjusts plasma treatment parameters by switching between different gas mixtures and treatment conditions. The plasma treatment conditions are changed between the first and second treatment stages, allowing selective etching in different directions. This dynamic approach maintains relative process simplicity while achieving high directional selectivity for metal gate film removal.
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
Enables the stable creation of complex and highly integrated semiconductor device structures by selectively removing metal-containing layers, enhancing controllability and reducing overetching risks.
Implementation Method 1
the metal-containing film is removed by etching with radicals generated from plasma after removal of the carbon-containing film
Data Source
AI summary
An object of the present invention is to provide a highly controllable plasma processing method capable of selectively removing a metal-containing layer. In the plasma processing method for plasma etching a metal-containing film formed on a formed pattern and covered with a carbon-containing film, after the carbon-containing film is removed, the metal-containing film is removed by etching with radicals generated from plasma.