Yttrium Oxide Coated Ceramic Dome for Semiconductor Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing etching processes for semiconductor device fabrication generate excessive polymers during the formation of gate structures, leading to defective processes, high maintenance costs, and decreased device yield due to the deposition of these polymers on chamber walls and wafers, necessitating frequent and costly cleaning and replacement of apparatus parts.
Innovation Solution
A method involving a ceramic dome coated with yttrium oxide (Y2O3) in the etching chamber, utilizing SF6/O2 gas for dry cleaning to effectively remove etch remnants and by-products, combined with a recovery process to maintain etch rate and minimize process changes, thereby reducing polymer generation and improving chamber cleanliness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching processes are used for gate structure formation, then high etch selectivity ratio is achieved, but excessive polymer generation occurs leading to chamber contamination and process defects
Solution Approach 1:
The patent changes the chemical parameters of the etching process by replacing conventional etching gases with SF6-based gas mixtures. This parameter change maintains the required etch selectivity for gate structures while significantly reducing polymer generation. The specific gas composition (SF6 with O2 or CF4) is optimized to balance etching performance and polymer control.
Solution Approach 2:
The patent substitutes the chemical mechanism of conventional etching with a plasma-based etching mechanism using SF6 gas. This substitution changes the reaction chemistry from carbon-based polymer-forming reactions to sulfur-fluorine based reactions that produce volatile by-products, thereby reducing polymer deposition while maintaining etch selectivity through plasma parameter control.
2Reliability
If frequent cleaning and replacement of chamber parts is performed to remove polymers, then chamber cleanliness is improved, but manufacturing costs and time consumption increase
Solution Approach 1:
The patent converts the harmful polymer deposition problem into a beneficial outcome by using the same etching process to simultaneously remove polymers from chamber surfaces. The SF6-based etching chemistry that reduces polymer generation also enables effective polymer removal through controlled etching of deposited materials, turning a maintenance burden into a self-cleaning process.
Solution Approach 2:
The etching chamber performs self-cleaning by using the SF6-based etching process to remove polymer deposits from its own surfaces. The process automatically eliminates contamination during normal operation without requiring external cleaning interventions, thereby maintaining chamber cleanliness while improving manufacturing efficiency.
3Object-affected harmful factors
If aluminum oxide coating is used on chamber walls, then initial protection is provided, but the coating is scrapped off by plasma leading to particle generation and defective processes
Solution Approach 1:
The patent transitions from using aluminum oxide coating to employing SF6-based plasma chemistry that is inherently compatible with chamber wall materials. The SF6 plasma creates a chemically inert environment that does not react with or degrade the chamber coating, thereby eliminating particle generation from coating scrapping while maintaining protective functions.
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 significantly decreases particle generation by approximately 70% or higher, reducing manufacturing costs, time consumption, and enhancing device yields by effectively removing polymers and stabilizing the etch process, while allowing for more efficient and convenient process manipulation.
Implementation Method 1
gases such as HBr, Cl2 and O2 gases are used as a main gas, and the polymers generated after the dry etching process are mixtures such as Si(Br,Cl)xOy, CHxOy or AlFx
Implementation Method 2
etching a gate structure formed on the wafer, thereby generating etch remnants; and removing the etch remnants by using a gas of SF6 as a main etch gas
Implementation Method 3
a chamber including a ceramic dome coated with a material having etch tolerance against a plasma
Data Source
AI summary
A method for fabricating a semiconductor device is provided. The method includes: loading a wafer into a chamber including a ceramic dome coated with a material having etch tolerance against a plasma; etching a gate structure formed on the wafer, thereby generating etch remnants; and removing the etch remnants by using a gas of SF6 as a main etch gas.