Bell Jar Cleaning Chamber for Metal Oxide Redeposition Control
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Solution Overview
Problem
Existing semiconductor device fabrication processes struggle to effectively remove metal oxide residue from conductive structures during cleaning, leading to redeposition of metal oxides onto the conductive structures and other layers, which can cause adhesion and contact resistance issues.
Innovation Solution
A cleaning apparatus and method utilizing a processing chamber with a bell jar structure, an oxygen source, and heating elements to remove metal oxide residue from conductive structures. The oxygen source promotes the redeposition of metal oxides onto the bell jar structure rather than the conductive structures, while the heating elements enhance the oxidation reaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional cleaning processes are used to remove metal oxide residue, then cleaning action is provided, but metal oxide residue redeposits onto conductive structures
Solution Approach 1:
A bell jar structure is introduced as an intermediary component between the plasma source and the substrate. The bell jar captures metal oxide residue during plasma cleaning and redirects it to deposit on the bell jar surface rather than on the conductive structures, preventing harmful redeposition while maintaining cleaning effectiveness
Solution Approach 2:
The invention converts the harmful redeposition of metal oxide residue onto conductive structures into a beneficial process by redirecting the residue to deposit on the bell jar structure instead. The harmful factor (redeposition) is transformed into a controlled process where residue accumulates on a sacrificial surface (bell jar) that can be easily removed or cleaned
2Temperature
If oxygen gas is introduced to promote oxidation, then metal oxide formation is enhanced, but redeposition onto conductive structures increases
Solution Approach 1:
The bell jar structure serves as an intermediary that intercepts metal oxide species in the plasma environment. By positioning the bell jar between the plasma source and substrate, it captures oxidized metal species and redirects them to deposit on the bell jar surface, preventing their harmful deposition on conductive structures while allowing oxygen to maintain its beneficial oxidation function
Solution Approach 2:
The invention creates different local environments: the region around the bell jar is designed to capture and accumulate metal oxide residue, while the substrate region maintains clean conditions. This spatial differentiation of deposition zones allows oxidation to proceed beneficially in one location while preventing harmful redeposition in another location
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 solution effectively removes metal oxide residue from conductive structures, preventing redeposition onto the structures and improving adhesion and contact resistance, thereby enhancing the reliability of semiconductor devices.
Implementation Method 1
an oxygen source coupled to the processing chamber and configured to input oxygen gas into the processing chamber
Implementation Method 2
a plasma coil arranged over the bell jar structure
Implementation Method 3
heating elements arranged inside the processing chamber and configured to increase a temperature of the processing chamber
Data Source
AI summary
In some embodiments, the present disclosure relates to a method that includes forming a dielectric layer over a conductive structure on a substrate. A removal process is performed to remove a portion of the dielectric layer to expose a portion of the conductive structure. The substrate is transported into a cleaning chamber having a wafer chuck below a bell jar structure. A cleaning process is performed to clean the exposed portion of the conductive structure by turning on a noble gas source to introduce a noble gas within the cleaning chamber, turning on an oxygen gas source to introduce oxygen within the cleaning chamber, applying a first bias to a plasma coil to form a plasma gas, and applying a second bias to the wafer chuck. The substrate is removed from the cleaning chamber. A conductive layer is formed over the dielectric layer and coupled to the conductive structure.