Capacitor Oxide Film Removal via Nitride Floating Pattern
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for manufacturing semiconductor capacitors face challenges in removing the capacitor oxide film without collapsing the lower electrode, leading to increased manufacturing costs and non-uniform charge capacity due to the need for expensive photo mask processes and difficulties in achieving uniform ZAZ coating.
Innovation Solution
A method involving the formation of an etching barrier film with cavities to skip the photo mask process, using a nitride film floating pattern as a mask to remove the capacitor oxide film, and ensuring the etching barrier film has a fine honeycomb shape with specific cavity diameters and densities to prevent electrode collapse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a wet dip-out process is used to remove capacitor oxide film, then the oxide film can be removed, but moisture penetrates between lower electrodes causing surface tension that generates leaning phenomenon and electrode collapse
Solution Approach 1:
A nitride floating pattern is introduced as an intermediary layer between the capacitor oxide film and the lower electrode. This mediator allows the oxide film to be removed while the nitride layer supports the lower electrode structure, preventing collapse during the wet dip-out process.
Solution Approach 2:
The nitride floating pattern is formed in advance before the oxide film removal process. This preliminary structural preparation ensures that when the oxide film is subsequently removed via wet dip-out, the lower electrode already has supporting structures in place to prevent leaning and collapse.
2Reliability
If the width of lower electrodes is increased to prevent collapsing, then electrode stability improves, but the height becomes higher maintaining aspect ratio causing leaning phenomenon again
Solution Approach 1:
Instead of increasing electrode width in the horizontal dimension, the solution introduces a vertical supporting structure (nitride floating pattern) that provides mechanical support in the vertical dimension. This allows maintaining the original electrode width while preventing collapse through the additional dimensional support.
3Reliability
If a nitride floating pattern is formed to prevent leaning phenomenon, then electrode stability improves, but manufacturing cost increases due to required photo mask process
Solution Approach 1:
The photo mask process is extracted and replaced with a self-aligned deposition method. The nitride floating pattern is formed through sequential deposition and selective removal processes that use previously formed structures as alignment references, eliminating the need for separate photo mask steps and reducing manufacturing cost.
4Manufacturing precision
If conventional photo mask process is used to form nitride floating pattern, then pattern precision is achieved, but manufacturing cost increases and ZAZ coating uniformity deteriorates
Solution Approach 1:
Instead of using photo masks to create patterns, the invention uses self-aligned deposition where the pattern is copied from previously formed structures. The nitride floating pattern aligns automatically with existing features through conformal deposition, achieving precision without the cost and complexity of photo mask processes.
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 reduces manufacturing costs by eliminating the need for expensive photo masks and allows for uniform ZAZ coating, ensuring the capacitor has sufficient capacitance without electrode collapse.
Implementation Method 1
A blanket-etching process is performed onto the etching barrier film including cavities until the capacitor oxide film is exposed. As a result, a nitride film floating pattern is formed.
Implementation Method 2
using a nitride film floating pattern as a mask to remove the capacitor oxide film
Implementation Method 3
An etching barrier film including cavities is formed over the capping oxide film... ensuring the etching barrier film has a fine honeycomb shape with specific cavity diameters and densities to prevent electrode collapse
Data Source
AI summary
A method for manufacturing a capacitor of a semiconductor device includes: forming an interlayer insulating film including a contact plug over a semiconductor substrate; forming a first stack film including a capacitor oxide film and a nitride film over the interlayer insulating film; etching the first stack film to form a first stack pattern and a contact hole that exposes the contact plug; forming a lower electrode in the contact hole; forming a capping oxide film continuously over the first stack pattern to form a bridge connecting the neighboring first stack patterns; forming an etching barrier film including cavities over the capping oxide film; performing a blanket etching process onto the etching barrier film including cavities until the capacitor oxide film is exposed to form a nitride film pattern; and removing the exposed capacitor oxide film.