Remote Plasma Cleaning for Semiconductor Wafer Interfaces
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Solution Overview
Problem
Existing semiconductor manufacturing processes face challenges in effectively cleaning the surface of semiconductor wafers to ensure proper adhesion and mechanical/electrical properties, particularly due to copper oxide and hydrocarbon residues, which can be exacerbated by direct plasma cleaning methods that also affect low-k dielectric materials and reduce system throughput.
Innovation Solution
The use of a remote plasma processing system with a load lock and ion filter to clean the wafer surface, allowing for efficient removal of metal oxides and hydrocarbons without subjecting the low-k dielectric to high-energy ions, thereby improving adhesion and maintaining system throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If direct plasma cleaning is used to remove copper oxide and hydrocarbons, then surface cleaning effectiveness is improved, but damage to low-k dielectric material increases
Solution Approach 1:
The plasma cleaning process is segmented into two distinct stages: a direct plasma stage for removing copper oxide and hydrocarbons, followed by a remote plasma stage for repairing damaged low-k dielectric material. This segmentation allows each stage to be optimized for its specific function, achieving effective cleaning while minimizing net damage to the dielectric.
Solution Approach 2:
Remote plasma acts as an intermediary repair mechanism between the aggressive direct plasma cleaning and the low-k dielectric material. The remote plasma provides gentle chemical treatment that repairs dielectric damage without the harsh physical bombardment of direct plasma ions, thereby protecting the dielectric while maintaining cleaning effectiveness.
2Manufacturing precision
If in situ plasma cleaning is performed in PECVD chamber, then surface cleaning is achieved, but system throughput is reduced
Solution Approach 1:
The plasma cleaning process is merged with the PECVD deposition process by performing both operations in the same chamber without breaking vacuum. The chamber transitions between plasma cleaning mode and PECVD deposition mode, eliminating the need for separate cleaning chambers or atmospheric transfer steps, thereby maintaining high system throughput.
Solution Approach 2:
The plasma cleaning process is performed continuously within the PECVD chamber workflow, maintaining vacuum conditions throughout. The chamber remains under vacuum during both cleaning and subsequent deposition operations, eliminating pump-down and re-pumping cycles, thus preserving continuous production flow and high throughput.
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
Remote plasma cleaning effectively reduces copper oxides and hydrocarbons, enhancing the adhesion of subsequent layers while minimizing damage to low-k dielectric materials, thus improving semiconductor device performance and maintaining high processing throughput.
Implementation Method 1
a remote plasma source configured to provide a remote plasma to the load lock
Implementation Method 2
Remote plasma cleaning effectively reduces copper oxides and hydrocarbons
Implementation Method 3
an ion filter disposed between the remote plasma source and the wafer pedestal
Data Source
AI summary
Embodiments related to the cleaning of interface surfaces in a semiconductor wafer fabrication process via remote plasma processing are disclosed herein. For example, in one disclosed embodiment, a semiconductor processing apparatus includes a processing chamber, a load lock coupled to the processing chamber via a transfer port, a wafer pedestal disposed in the load lock and configured to support a wafer in the load lock, a remote plasma source configured to provide a remote plasma to the load lock, and an ion filter disposed between the remote plasma source and the wafer pedestal.