Plasma Etch Chamber Metal Sputtering for Hard Mask Selectivity
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Solution Overview
Problem
The semiconductor industry faces challenges in achieving high aspect ratio feature patterning with accurate, precise, and profile-controlled plasma processing, particularly at atomic scale dimensions, due to limitations in mask height and etch selectivity of conventional mask materials.
Innovation Solution
A plasma etching system and method that incorporates metal sputtering, where a refractory metal is sputtered from a chamber part with a metal surface within the plasma etch chamber, deposited onto a patterned hard mask layer, and used to selectively etch the underlying layer, enhancing etch selectivity and process control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional mask materials are used for high aspect ratio feature patterning, then the mask height and etch selectivity are limited, but the process complexity and manufacturing difficulty increase when trying to achieve higher aspect ratios
Solution Approach 1:
A metal-containing coating is applied to the top electrode as an intermediary material source. This coating acts as a mediator that releases metal atoms into the plasma, which then deposit onto the hard mask to form a protective metal layer in-situ during the etch process, improving etch selectivity without requiring separate deposition steps
Solution Approach 2:
The invention changes the physical and chemical parameters of the etch environment by introducing metal atoms from the sputtering coating into the plasma. This alters the plasma composition and reactivity, enabling enhanced etch selectivity and profile control for high aspect ratio features
2Measurement precision
If plasma processing is used to pattern features at atomic scale dimensions, then accuracy and precision improve, but profile control becomes more challenging
Solution Approach 1:
The metal-containing coating on the top electrode serves as an intermediary that provides metal atoms to the plasma, which then deposit as a protective layer on the mask sidewalls. This intermediary metal layer improves profile control by protecting the mask during etching, enabling better vertical sidewall formation in high aspect ratio features
Solution Approach 2:
The invention creates a composite plasma environment containing both the primary etch chemistry and metal atoms from the sputtering coating. This composite plasma provides both the etching capability for accuracy and the metal deposition for profile control, simultaneously addressing both precision requirements
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 achieves improved etch selectivity and process control for high aspect ratio feature patterning, enabling the fabrication of advanced 3D semiconductor devices with higher aspect ratios and improved precision.
Implementation Method 1
exposing the surface of the chamber part to the plasma to sputter the refractory metal from the surface of the chamber part
Implementation Method 2
deposit the refractory metal onto a portion of the patterned hard mask layer
Data Source
AI summary
A method of processing a substrate that includes: loading the substrate into a plasma etch chamber, the substrate including a patterned hard mask layer and an underlying layer, the plasma etch chamber including: a chamber part having a surface including a refractory metal; and a first electrode; flowing a process gas into the plasma etch chamber; while flowing the process gas, applying a source power to the first electrode of the plasma etch chamber to generate a plasma in the plasma etch chamber; exposing the surface of the chamber part to the plasma to sputter the refractory metal from the surface of the chamber part; and exposing the substrate to the plasma to deposit the refractory metal onto a portion of the patterned hard mask layer and etch the underlying layer selectively to the patterned hard mask layer.