Molecular Beam Enhanced GCIB Etch Selectivity
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Solution Overview
Problem
Conventional etch processes face challenges in achieving practical etch rates and acceptable etch selectivity for new materials used in semiconductor processing, such as Si-containing, Ge-containing, and metal-containing materials, while maintaining profile control and uniformity across semiconductor substrates.
Innovation Solution
A gas cluster ion beam (GCIB) processing system is employed, which includes a GCIB generating system and molecular beam sources interacting with the substrate in a vacuum chamber, allowing for controlled etching, deposition, or smoothing of substrates by adjusting the angle of incidence and composition of the GCIB and molecular beams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional plasma etch processes are used to etch new materials (high-k dielectrics, metal electrodes), then the etch process can be applied to existing materials, but the etch rate and etch selectivity become insufficient for new materials
Solution Approach 1:
The patent changes the fundamental parameters of the etch process by transitioning from plasma-based chemistry to GCIB physical bombardment. This involves changing the etching mechanism from chemical reaction to physical sputtering, altering beam energy, gas composition, and process conditions to achieve both high etch rates and excellent selectivity for new materials like high-k dielectrics and metal electrodes
Solution Approach 2:
The patent replaces the chemical plasma etch system with a physical GCIB system. Instead of using reactive plasma species to chemically etch materials, the invention uses accelerated gas cluster ions to physically bombard and remove material through momentum transfer, enabling effective etching of materials that are resistant to conventional chemical etching
2Area of stationary object
If conventional etch processes are applied uniformly across the substrate, then coverage is achieved, but profile control and uniformity deteriorate
Solution Approach 1:
The patent implements local quality by allowing different regions of the substrate to receive optimized etching conditions. The GCIB system can be configured with specific beam angles, energies, and gas compositions that are tailored to local feature requirements, enabling precise profile control while maintaining uniform coverage across the entire substrate
Solution Approach 2:
The patent introduces dynamics by making the GCIB process conditions adjustable and adaptable during processing. Beam energy, gas composition, and incidence angles can be dynamically optimized for different materials and feature geometries, allowing the system to maintain excellent profile control and uniformity across diverse substrate areas
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 GCIB processing system achieves targeted etch process metrics like etch rate, selectivity, and surface roughness control, enabling efficient and uniform etching of various materials, including Si-containing, Ge-containing, and metal-containing materials, while maintaining substrate integrity.
Implementation Method 1
a gas cluster ion beam (GCIB) is formed and directed onto a substrate to etch, deposit on, or smooth a surface of the substrate
Implementation Method 2
the GCIB may be used to etch, deposit on, or smooth a surface of the substrate
Implementation Method 3
a molecular beam generating system that may be used in conjunction to treat a substrate within a vacuum chamber
Data Source
AI summary
A method and system for performing gas cluster ion beam (GCIB) etch processing of various materials is described. In particular, the GCIB etch processing includes using one or more molecular beams to optimize pressure at localized regions of the ion beam.