Amorphous Metal Hardmask Nitrogen Control for Hole Pattern Distortion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Highly-integrated semiconductor devices face distortions in hole patterns due to grain boundaries in metal hardmasks during the process of forming high aspect ratio patterns, which affects the etch target layer's uniformity and reliability.
Innovation Solution
A method involving the formation of an amorphous metal hardmask with nitrogen content between 15 and 25 atomic percentage, using alternating current bias and direct current power in a sputtering process to generate plasma, reducing distortions by minimizing crystallization and maintaining an amorphous state for improved etching characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a metal hardmask with high etch selectivity is used to form high aspect ratio hole patterns, then the etching performance is improved, but grain boundaries in the metal hardmask cause undesired distortions in the hole pattern
Solution Approach 1:
The patent changes the physical state parameter of the metal hardmask from crystalline to amorphous. By controlling the deposition process to form an amorphous metal layer, the material structure is fundamentally altered to eliminate grain boundaries, thereby preventing pattern distortions while maintaining etching performance
Solution Approach 2:
The patent creates a composite structure by incorporating nitrogen into the metal layer to form an amorphous metal nitride compound. This composite material approach allows the hardmask to maintain both the desired etch selectivity and the amorphous structure free from grain boundaries
2Stability of the object's composition
If nitrogen content in the amorphous metal layer is increased to maintain amorphous state, then grain boundary formation is reduced, but excessive nitrogen may affect etching characteristics
Solution Approach 1:
The patent optimizes the nitrogen content parameter within a specific range (5-30 atomic percent) to achieve the desired balance. This parameter optimization ensures the metal layer maintains its amorphous state while preserving appropriate etching characteristics for the etch target layer
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 method effectively reduces distortions in hole patterns and enhances the reliability and productivity of semiconductor devices by using an amorphous metal hardmask with controlled nitrogen composition, ensuring uniformity and stability in high aspect ratio features.
Implementation Method 1
generating plasma by supplying an inert gas and a nitrogen gas to the process chamber
Implementation Method 2
forming an amorphous metal layer on the etch target layer, the amorphous metal layer including nitrogen
Data Source
AI summary
A method of manufacturing a semiconductor device includes forming an etch target layer on a substrate; forming an amorphous metal layer on the etch target layer, the amorphous metal layer comprising nitrogen between 15 atomic percentage (at %) and 25 at %; forming an amorphous metal hardmask by patterning the amorphous metal layer; and etching the etch target layer by using the amorphous metal hardmask as an etching mask.