Single-Chamber Dielectric Gap Fill Using In-Situ Deposition-Etch
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Solution Overview
Problem
Existing methods for filling narrow trenches with high aspect ratios in microelectronics device fabrication face challenges such as void formation, seam issues, increased processing time, and contamination due to the transfer of wafers between deposition and etch chambers, leading to poor film quality and chamber component degradation.
Innovation Solution
A single-chamber deposition-etch scheme using a resonant cavity microwave plasma source with a monolithic alumina showerhead, allowing for conformal deposition and non-conformal etching within the same chamber to fill trenches effectively, minimizing interface formation and reducing processing time and contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple cycles of deposition and etch are performed using separate chambers, then gapfilling process window is improved, but processing time increases and chamber contamination occurs
Solution Approach 1:
The patent combines deposition and etch processes into a single chamber system, eliminating the need to transfer wafers between separate deposition and etch chambers. This merging of functions maintains the multi-cycle deposition-etch process window for quality gapfilling while reducing processing time by eliminating transfer steps and chamber switching.
Solution Approach 2:
The single chamber is designed to perform multiple functions - both deposition and etching operations - within the same processing environment. This multi-functionality allows the chamber to handle alternating deposition-etch cycles without requiring separate specialized chambers, thereby reducing overall processing time while maintaining process quality.
2Manufacturing precision
If wafer transfer between deposition and etch chambers is performed, then deposition quality is improved, but surface reactions such as oxidation occur
Solution Approach 1:
By merging deposition and etch processes into a single chamber, the patent eliminates the intermediate transfer step where wafers are exposed to ambient environment. This prevents surface reactions such as oxidation that would occur during chamber transfer, while still maintaining high deposition quality through controlled in-situ processing.
Solution Approach 2:
The single chamber maintains a controlled inert atmosphere throughout the entire deposition-etch cycle, preventing unwanted surface reactions. The chamber environment remains consistent and protective throughout all processing steps, eliminating exposure to reactive ambient conditions that would cause oxidation or other surface degradation.
3Ease of manufacture
If etch chemistries are used to remove in-situ coatings, then chamber maintenance is improved, but metal contamination and defects increase
Solution Approach 1:
The patent modifies the etch chemistry parameters and composition to achieve effective removal of in-situ coatings without causing metal contamination. By adjusting etch selectivity, chemistry composition, and process parameters, the system maintains chamber cleanliness while preventing contamination and defects during the etching process.
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 enables high-quality film deposition and etching in a single chamber, reducing processing time and costs while maintaining film integrity, thus addressing void and seam issues and minimizing chamber degradation.
Implementation Method 1
A single-chamber deposition-etch scheme using a resonant cavity microwave plasma source
Implementation Method 2
monolithic alumina showerhead
Data Source
AI summary
Methods for filling a substrate feature with a seamless dielectric gap fill are described. Methods comprise sequentially depositing a film with a seam and partially etching the film in the same processing chamber. Methods and apparatus allow for the same hardware to be used for PEALD deposition of a film as well as plasma etch of the film.