Batch CVD Silicon Oxide Filling via Periodic Etching
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Solution Overview
Problem
In the fabrication of integrated circuits, the advancement in IC integration leads to narrow line-and-space patterns, making it difficult for silicon oxide films to fill spaces uniformly using CVD methods, resulting in voids and potential contamination or defects during etching and metallization processes, especially in batch-type CVD apparatuses where uniformity is lacking.
Innovation Solution
A batch-type film deposition method and apparatus that alternately repeats the deposition and etching steps using silicon-containing, oxygen-containing, fluorine-containing, and ammonia gases to improve filling characteristics and uniformity on substrates with concave patterns, ensuring thorough filling of spaces without voids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a batch-type CVD apparatus is used to deposit silicon oxide film, then throughput is improved, but filling uniformity deteriorates
Solution Approach 1:
The patent applies periodic action by alternating deposition and etching cycles. During deposition, silicon oxide is deposited on substrates; during etching, the deposited film is partially removed. This periodic alternation allows precursors to penetrate deeper into concave parts between cycles, achieving uniform filling in batch-type apparatus while maintaining high throughput.
Solution Approach 2:
The etching step serves as a preliminary action that removes excess deposited material before the next deposition cycle. By etching the silicon oxide film deposited on substrates and then repeating deposition, the process prepares the surface for better precursor penetration in subsequent cycles, enabling uniform filling of narrow spaces.
2Speed
If CVD method is used to fill narrow spaces, then deposition speed is improved, but precursor penetration deteriorates
Solution Approach 1:
By periodically alternating fast deposition with etching, the process achieves both high deposition speed and deep precursor penetration. The etching intervals allow precursors to reach the bottom of narrow spaces, while deposition cycles build up the film quickly, resolving the contradiction between speed and penetration.
Solution Approach 2:
The alternating deposition-etching-deposition sequence maintains continuous useful action. Rather than stopping deposition entirely, the process continues building film while periodically removing excess to enable penetration, ensuring both speed and uniformity are achieved through continuous cyclic operation.
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 achieves improved filling characteristics and uniformity in silicon oxide film deposition, preventing voids and defects, thereby enhancing the reliability of subsequent processes in integrated circuit fabrication, even in batch-type CVD apparatuses.
Implementation Method 1
depositing a silicon oxide film on the plural substrates by supplying a silicon-containing gas and an oxygen-containing gas to the reaction chamber
Implementation Method 2
etching the silicon oxide film deposited on the plural substrates in the step of depositing by supplying a fluorine-containing gas and an ammonia gas to the reaction chamber
Data Source
AI summary
A disclosed film deposition method includes steps of loading plural substrates each of which includes a pattern including a concave part in a reaction chamber in the form of shelves; depositing a silicon oxide film on the plural substrates by supplying a silicon-containing gas and an oxygen-containing gas to the reaction chamber; etching the silicon oxide film deposited on the plural substrates in the step of depositing by supplying a fluorine-containing gas and an ammonia gas to the reaction chamber; and alternately repeating the step of depositing and the step of etching.