ALD Oxide Gap Fill With Sputtering for Seam Reduction
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Solution Overview
Problem
Semiconductor device fabrication processes face challenges in achieving high-quality oxide films, particularly in filling gaps, where seams often form during deposition, leading to reduced film density and increased failure rates.
Innovation Solution
A method involving the use of a dual radio frequency plasma source with a high frequency and low frequency component, combined with atomic layer deposition and sputtering, to deposit oxide material into patterned features, reducing seam formation by re-depositing oxide material deeper into features and altering the gap shape, thereby improving film density and reducing voids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional CVD or plasma enhanced deposition is used to deposit oxide films, then deposition can be achieved, but seams form during deposition leading to reduced film density and increased failure rates
Solution Approach 1:
The patent changes the deposition parameters by implementing a dual-frequency RF plasma source with specific power ratios (LF/HF between 0.1-10), controlling plasma density and ion bombardment energy to achieve seam-free deposition. The process also controls pressure (10-200 mTorr) and temperature (25-400°C) parameters to optimize film quality and eliminate seams that cause device failures
Solution Approach 2:
The patent employs dynamic control of plasma conditions during deposition by modulating the dual-frequency RF power delivery. The low-frequency component (100 kHz-10 MHz) and high-frequency component (1 MHz-1 GHz) are dynamically adjusted during the deposition process to control ion flux and radical density, enabling real-time optimization of deposition quality and seam prevention
2Manufacturing precision
If deposition is performed in gaps or high aspect ratio features, then complete filling can be achieved, but seam formation occurs reducing film density
Solution Approach 1:
The patent applies local quality control by using the dual-frequency RF plasma to create localized variations in ion bombardment and radical distribution within the gap features. The low-frequency component provides ion-directed transport that preferentially deposits material in hard-to-reach areas, while the high-frequency component ensures uniform conformal coverage, achieving both complete gap filling and high film density without seams
Solution Approach 2:
The patent employs a composite deposition approach combining plasma-enhanced chemical vapor deposition mechanisms with physical vapor deposition characteristics through ion bombardment. This composite process uses both chemical reactions (from RF-generated radicals) and physical sputtering-like effects (from ion bombardment) to achieve superior gap filling with dense, seam-free films that neither mechanism alone could produce
3Reliability
If conventional deposition methods are used, then deposition can be achieved, but voids form in the deposited film
Solution Approach 1:
The patent maintains continuous plasma generation during deposition through dual-frequency RF coupling, ensuring uninterrupted radical generation and ion bombardment. This continuous action prevents the formation of voids by maintaining consistent deposition rates and film density throughout the entire deposition process, achieving both high film integrity and perfect conformality across the substrate
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 effectively fills features with minimal seams, enhancing the quality of oxide films and reducing the risk of device failure by ensuring a dense and conformal deposition of oxide material, even in features with high aspect ratios.
Implementation Method 1
a plasma generated by a dual radio frequency (RF) plasma source including a high frequency (HF) component and a low frequency (LF) component
Implementation Method 2
sputtering the oxide material using an inert gas in the presence of a plasma
Implementation Method 3
depositing oxide material into the patterned features by an atomic layer deposition (ALD) process
Data Source
AI summary
Methods and apparatuses for depositing material into features are described herein. Methods involve depositing an oxide material and then sputtering the oxide material to reduce seams. The oxide material may be deposited by an ALD process.