Directional Silicon Gap Fill for Seam-Free Narrow Features
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Solution Overview
Problem
Conventional gap filling operations in semiconductor manufacturing face challenges with void and seam formation in narrow features with high aspect ratios, leading to device performance issues and subsequent processing difficulties.
Innovation Solution
A method involving sequential deposition and etch operations using silicon-and-carbon-containing precursors, hydrogen-containing precursors for etching, and nitrogen-containing precursors for doping, controlled by pulsing bias power and plasma power, to fill features with a densified and seam-free material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If continuous deposition is performed to fill narrow features, then the feature is filled with material, but voids and seams form within the feature
Solution Approach 1:
The patent applies periodic action by alternating between deposition and etching cycles. During deposition, material is deposited into the feature; during etching, material is removed from sidewalls. This periodic alternation prevents void and seam formation by continuously adjusting the fill profile, achieving complete void-free filling of narrow high aspect ratio features.
Solution Approach 2:
The filling process is segmented into multiple discrete cycles, each consisting of a deposition step followed by an etching step. Rather than performing a single continuous deposition, the process divides the fill operation into manageable segments that can be controlled and optimized independently, allowing precise management of material deposition and removal.
2Manufacturing precision
If deposition occurs at the top and along sidewalls of the feature, then the feature is filled, but the feature is pinched off between sidewalls
Solution Approach 1:
The periodic alternation between deposition and etching prevents feature pinch-off. During deposition, material accumulates at the top and sidewalls; during the subsequent etching step, material is selectively removed from the sidewalls. This periodic cycle prevents the sidewalls from converging and pinching off the feature, maintaining open geometry throughout the fill process.
Solution Approach 2:
Material deposited on the sidewalls during the deposition step is intentionally discarded during the etching step. Rather than allowing this sidewall material to accumulate and cause pinch-off, the process deliberately removes it, recovering the feature's original geometry while still achieving fill of the feature interior.
3Manufacturing precision
If multiple processing steps are used to prevent voids, then fill quality improves, but process complexity increases
Solution Approach 1:
The patent merges the deposition and etching operations into a single integrated process chamber and procedure. Rather than performing deposition in one chamber and etching in another separate chamber (which would require multiple handling steps), both operations are combined in one system, reducing overall process complexity while achieving seam-free fill through the alternating cycles.
Solution Approach 2:
The processing chamber is designed with multi-functionality, capable of performing both deposition and etching operations. By making the chamber universal and able to switch between different process modes, the system avoids the complexity of multiple specialized chambers and handling steps, achieving simple seam-free fill through alternating cycles within a single system.
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 effectively limits sidewall coverage and prevents void formation, providing a seamless and dense fill in narrow features, enhancing device quality and performance.
Implementation Method 1
forming plasma effluents of the silicon-containing precursor and the carbon-containing precursor. depositing a silicon-and-carbon-containing material on the substrate
Implementation Method 2
etching the silicon-and-carbon-containing material from a sidewall of the feature within the substrate with the plasma effluents of the hydrogen-containing precursor
Implementation Method 3
doping the silicon-and-carbon-containing material with nitrogen from the plasma effluents of the nitrogen-containing precursor
Data Source
AI summary
Exemplary processing methods may include providing a silicon-containing precursor and a carbon-containing precursor to a processing region of a semiconductor processing chamber. A substrate may be housed in the processing region. The substrate may define a feature within the substrate. The methods may include forming plasma effluents of the silicon-containing precursor and the carbon-containing precursor. The methods may include depositing a silicon-and-carbon-containing material on the substrate. The methods may include providing a hydrogen-containing precursor to the processing region of the semiconductor processing chamber, forming plasma effluents of the hydrogen-containing precursor, and etching the silicon-and-carbon-containing material from a sidewall of the feature within the substrate. The methods may include providing a nitrogen-containing precursor to the processing region of the semiconductor processing chamber, forming plasma effluents of the nitrogen-containing precursor, and doping the silicon-and-carbon-containing material with nitrogen.