Silicon Oxide Gap Fill Using Plasma Etch-Deposition Cycles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional deposition methods in semiconductor manufacturing often result in voids within trenches due to high aspect ratios, affecting device quality and limiting the fabrication of smaller semiconductor features.
Innovation Solution
A capacitively coupled plasma is used between a substrate support and a showerhead in a semiconductor processing chamber, with oxygen flow from beneath the support, enabling deposition-etch-deposition processes to form oxide films within trenches without voids, utilizing controlled plasma conditions and multiple deposition steps to achieve seamless gap-filling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If chemical vapor deposition is used to fill trenches, then oxide films are deposited, but voids form within the trenches due to high aspect ratios
Solution Approach 1:
The deposition process is divided into multiple sequential deposition operations with etch steps in between. The first deposition fills the lower portion of the trench, the etch step removes material from the top to create an opening, and the second deposition fills the upper portion. This segmentation allows complete trench filling without void formation that would occur in a single continuous deposition operation.
Solution Approach 2:
The process employs periodic alternation between deposition and etching operations. Plasma is periodically activated and deactivated to switch between deposition mode and etching mode. This periodic action enables the deposition-etch-deposition sequence that successfully fills high aspect ratio trenches by removing formed material and allowing continued deposition access.
2Manufacturing precision
If plasma deposition is used to improve uniformity, then control is enhanced, but process complexity increases
Solution Approach 1:
The process utilizes changes in plasma parameters (activation and deactivation) to switch between deposition and etching modes. By controlling plasma presence and gas composition, the same equipment performs multiple functions with precise parameter adjustment, achieving uniform deposition while managing complexity through parameter control rather than additional hardware.
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 method allows for improved uniformity and control of deposition and etch processes, reducing void formation and enhancing the fabrication of smaller semiconductor features with improved yield and quality.
Implementation Method 1
depositing a first oxide film within the trench
Implementation Method 2
forming a first plasma of the precursor in the processing region
Implementation Method 3
etching the first oxide film, while flowing the oxygen-containing precursor
Data Source
AI summary
Exemplary deposition methods may include introducing a precursor into a processing region of a semiconductor processing chamber via a faceplate of the semiconductor processing chamber. The methods may include flowing an oxygen-containing precursor into the processing region from beneath a pedestal of the semiconductor processing chamber. The pedestal may support a substrate. The substrate may define a trench in a surface of the substrate. The methods may include forming a first plasma of the precursor in the processing region of the semiconductor processing chamber. The methods may include depositing a first oxide film within the trench. The methods may include forming a second plasma in the processing region. The methods may include etching the first oxide film, while flowing the oxygen-containing precursor. The methods may include re-forming the first plasma in the processing region. The methods may also include depositing a second oxide film over the etched oxide film.