Semiconductor Substrate Filling via Selective Etching
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Solution Overview
Problem
Existing semiconductor manufacturing processes face challenges in filling concave portions on substrates with films without leaving hollow portions or gaps, particularly when the aspect ratio of the concave features is high, leading to incomplete filling and etching damage.
Innovation Solution
A method involving the formation of a first film with a hollow portion, followed by selective etching and modification using specific precursors and etching agents, including oxygen and hydrogen fluoride, to create a surface suitable for a second film deposition that fills the concave portion without gaps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a film is formed to fill a concave portion with high aspect ratio, then the filling completeness improves, but hollow portions and gaps remain inside the film
Solution Approach 1:
The patent segments the film formation process into multiple stages: first forming a film that fills the concave portion, then selectively removing portions to eliminate hollow spaces, and finally forming additional film layers. This multi-stage approach divides the complex filling problem into manageable steps that ensure complete void-free filling.
Solution Approach 2:
The patent performs preliminary actions by first forming a film that completely fills the concave portion, then selectively removing specific portions (side walls and upper parts) before final film formation. This preliminary removal of excess material prevents hollow portions from forming in the final structure.
2Reliability
If etching is performed to remove film portions, then hollow portions are eliminated, but etching damage occurs on the film
Solution Approach 1:
The patent applies local quality by selectively removing only specific portions of the film (side walls and upper parts) while preserving the film in the concave portion. This selective removal eliminates hollow portions while minimizing etching damage to the areas that need to be retained.
Solution Approach 2:
The patent introduces an intermediary material layer between the film to be etched and the substrate. This intermediary layer protects the film from direct etching damage while allowing selective removal of unwanted portions to eliminate hollow spaces.
3Manufacturing precision
If multiple processing steps are performed, then filling quality improves, but process complexity increases
Solution Approach 1:
The patent merges multiple processing steps into an integrated sequence: film formation, selective removal, and additional film formation are combined in a coordinated manner. This merging approach improves filling quality while managing process complexity through systematic integration of steps.
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 improves the uniformity and quality of film filling in concave portions by controlling the etching process and reducing damage, ensuring a seamless and void-free filling of the substrate features.
Implementation Method 1
modifying a portion of the first film using a modifying agent
Implementation Method 2
selectively etching the modified portion of the first film using the etching agent
Implementation Method 3
forming the second film on the first film of which the portion is etched, using a second precursor
Data Source
AI summary
There is provided a technique that includes filling a concave portion formed on a surface of a substrate with a first film and a second film by performing: (a) forming the first film having a hollow portion using a first precursor so as to fill the concave portion formed on the surface of the substrate; (b) etching a portion of the first film which makes contact with the hollow portion, using an etching agent; and (c) forming the second film on the first film of which the portion is etched, using a second precursor, wherein (b) includes performing, a predetermined number of times: (b-1) modifying a portion of the first film using a modifying agent; and (b-2) selectively etching the modified portion of the first film using the etching agent.