Selective Silicon Oxide Deposition on Dielectrics for Fine Patterning
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Solution Overview
Problem
The challenge of forming features with reduced dimensions in semiconductor devices is exacerbated by the difficulty in patterning conductive, semi-conductive, and insulative layers due to the decreasing dimensions of semiconductor devices.
Innovation Solution
A method for selective deposition of dielectric layers on structures with alternating silicon oxide and silicon nitride layers using silicon-containing precursors and inhibitor materials, where the precursors and inhibitors are chosen to have specific activation energies and physisorption properties to selectively adhere to and protect the respective dielectric surfaces, allowing for precise deposition of silicon oxide or silicon nitride layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional patterning processes (dry or wet etching) are used to form features, then the manufacturing process can be completed, but the manufacturing precision deteriorates as dimensions decrease
Solution Approach 1:
The patent applies preliminary action by selectively depositing a protective dielectric layer on specific regions (e.g., silicon oxide regions) before performing etching operations. This pre-protection strategy prevents unwanted etching on protected regions, enabling precise feature formation at reduced dimensions without compromising manufacturing precision
Solution Approach 2:
The patent implements local quality by creating spatially varying properties on the substrate surface through selective deposition. Different regions receive different protective treatments based on their material composition (silicon oxide vs. silicon nitride), allowing precise control over which areas are protected during subsequent etching processes, thereby maintaining manufacturing precision at smaller feature sizes
2Manufacturing precision
If selective deposition is achieved through appropriate precursor and inhibitor selection, then deposition selectivity improves, but process complexity increases
Solution Approach 1:
The patent utilizes parameter changes by carefully selecting precursors and inhibitors with specific chemical properties (reactivity, adsorption characteristics) that enable selective deposition. By adjusting chemical parameters such as precursor reactivity and inhibitor strength, the process achieves high deposition selectivity on different dielectric materials
Solution Approach 2:
The patent employs inhibitor materials as intermediaries that temporarily modify surface properties to prevent unwanted deposition or etching. These inhibitor layers act as mediators between the deposition/etching process and the underlying dielectric materials, enabling selective processing while managing process complexity through controlled chemical interactions
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
Enables the formation of features with reduced dimensions by ensuring selective deposition on specific dielectric surfaces, protecting the unprotected layers from subsequent process steps, thereby improving the patterning process efficiency and precision.
Implementation Method 1
an activation energy, which leads to chemisorption from physisorption, of the silicon-containing precursor on an exposed surface of silicon oxide is less than an activation energy of the silicon-containing precursor on an exposed surface of silicon nitride
Implementation Method 2
Molecules of the oxygen-containing precursor react with the molecules of the silicon-containing precursor to form a silicon oxide sub-layer of the third dielectric layer
Implementation Method 3
physisorption of the inhibitor material on the exposed surface of silicon nitride is more stable than physisorption of the inhibitor material on the exposed surface of the silicon oxide
Data Source
AI summary
A method includes forming a structure, and the structure includes a first dielectric layer made of silicon oxide and a second dielectric layer made of silicon nitride. The method further includes performing a selective deposition process for depositing a third dielectric layer made of silicon oxide on the first dielectric layer. Performing the selective deposition process includes performing one or more deposition cycles. Performing a deposition cycle includes introducing a silicon-containing precursor over the structure. The silicon-containing precursor comprises a siloxane material having a chemical formula SiaHb(CH3)2a+1−b—O—SicHd(CH3)2c+1−d, where a, c=1 or 2, and b, d≤2a+1. Molecules of the silicon-containing precursor are selectively adsorbed on an exposed surface of the first dielectric layer. Performing the deposition cycle further includes introducing an oxygen-containing precursor over the structure. Molecules of the oxygen-containing precursor react with the molecules of the silicon-containing precursor to form a silicon oxide sub-layer of the third dielectric layer.