Gas Cluster Ion Beam Etch Profile Control via Divergence
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Solution Overview
Problem
Conventional etch processes face challenges in achieving practical etch rates and acceptable etch selectivity for new exotic materials used in semiconductor processing, while also struggling with uniform profile control during pattern etching.
Innovation Solution
The method involves using a gas cluster ion beam (GCIB) to etch substrates, where a mask layer with a pattern is formed on the substrate, and the sidewall profile of the feature pattern is controlled by adjusting the beam divergence of the GCIB, allowing for precise control of the etch profile through modifications in beam acceleration potential, stagnation pressure, and angular distribution function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional plasma etch processes are used to etch exotic materials, then etch selectivity may be achieved, but etch rate and profile control uniformity deteriorate
Solution Approach 1:
The patent applies parameter changes by transitioning from conventional plasma etching to gas cluster ion beam (GCIB) etching, which utilizes different physical and chemical parameters. The GCIB process employs clustered ions with specific energy distributions and angular divergences that enable simultaneous achievement of high etch rates and excellent profile control on exotic materials like high-k dielectrics and metal gates, resolving the contradiction between etch rate and profile control uniformity
2Manufacturing precision
If beam divergence of GCIB is increased, then etch profile control improves, but directional etching capability deteriorates
Solution Approach 1:
The patent applies dynamics by making the beam divergence angle a variable parameter that can be dynamically adjusted during the etching process. By controlling the angular distribution of the GCIB, the system can optimize between sidewall profile control (requiring higher divergence) and directional etching speed (requiring lower divergence), allowing adaptive optimization for different etching stages and material layers
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 enables improved etch anisotropy and uniformity, enhancing the ability to etch complex patterns on substrates with exotic materials by tuning the etch rate and profile control, addressing the limitations of conventional etch processes.
Implementation Method 1
etching a feature pattern into the substrate from the pattern in the mask layer using a gas cluster ion beam (GCIB)
Implementation Method 2
gas cluster ion beam (GCIB)
Data Source
AI summary
A method of etching a substrate is described. In one embodiment, the method includes preparing a mask layer having a pattern formed therein on or above at least a portion of a substrate, etching a feature pattern into the substrate from the pattern in the mask layer using a gas cluster ion beam (GCIB), and controlling a sidewall profile of the feature pattern etched into the substrate by adjusting a beam divergence of the GCIB.