ALD Dielectric Gapfill With Inhibitor Plasma for Void-Free Features
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing substrate processing systems face challenges in achieving void-free fill of high aspect ratio features, as deposition methods like ALD often result in seams or voids at the center of features, which can lead to unintended conductive material filling and short circuits.
Innovation Solution
A method combining atomic layer deposition (ALD) with inhibitor plasma and etching cycles, where inhibitor plasma gas is used to selectively inhibit deposition in upper feature portions, followed by etching to ensure complete fill without voids, utilizing a controller to manage gas delivery and plasma generation for precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If atomic layer deposition (ALD) is used to gapfill high aspect ratio features, then the feature can be filled with dielectric film, but a seam or void remains at the center of the feature
Solution Approach 1:
The gapfill process is divided into multiple sequential ALD cycles with intermediate etching steps. Each ALD cycle deposits a portion of the dielectric film, and the intermediate etching removes excess material from upper portions, preventing void formation and enabling complete feature fill without seams
Solution Approach 2:
The process employs periodic alternation between deposition and etching operations. ALD cycles are performed repeatedly with intermediate etching steps, creating a rhythmic sequence of depositing and removing material that ensures uniform fill while eliminating voids at the feature center
2Manufacturing precision
If multiple ALD cycles are performed to fill high aspect ratio features, then more complete fill is achieved, but deposition time increases
Solution Approach 1:
Excess dielectric material deposited in upper portions of features during ALD cycles is selectively removed through intermediate etching steps. This extraction of unnecessary material prevents the need for excessive deposition cycles, reducing total processing time while maintaining complete feature fill
Solution Approach 2:
The process intentionally deposits more material than immediately needed in each ALD cycle, then removes the excess through intermediate etching. This partial over-deposition followed by selective removal is more efficient than attempting to deposit precisely the required amount, reducing total cycle time
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 allows for void-free gapfill of high aspect ratio features with dielectric film, reducing the risk of short circuits by ensuring uniform deposition and preventing seam formation, thereby enhancing the reliability of subsequent integration steps.
Implementation Method 1
perform atomic layer deposition (ALD) to deposit film in a feature of the substrate
Implementation Method 2
supplying an inhibitor plasma gas to the processing chamber and striking plasma in the processing chamber to inhibit deposition in upper portions of the feature
Implementation Method 3
supplying an etch gas to the processing chamber to etch the film in the feature of the substrate
Data Source
AI summary
A plasma generating system generates plasma in a processing chamber. A controller is configured to: a) perform atomic layer deposition (ALD) N times to deposit film in a feature of the substrate; b) after performing a) M of the N times, supply an inhibitor plasma gas to the processing chamber and strike plasma in the processing chamber to create a passivated surface more on upper portions of the feature as compared to lower portions of the feature to inhibit the atomic layer deposition in the upper portions of the feature as compared to the lower portions of the feature; c) supply an etch gas to the processing chamber to etch the film more in the upper portions of the feature than in the lower portions in the feature of the substrate following b); and d) repeat a) to c) one or more times to gapfill the feature without voids.