Fin Structure Passivation Layer Formation Method
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Solution Overview
Problem
The semiconductor industry faces challenges in forming reliable semiconductor devices at smaller sizes due to increased complexity and difficulty in fabrication processes as feature sizes decrease, leading to issues with device reliability and performance.
Innovation Solution
A semiconductor device structure is formed using fin structures with a passivation layer created through a thermal process, which includes an interfacial layer, an oxygen scavenging layer, and a barrier layer to enhance device characteristics by reducing defects and improving interface quality, and a method involving surface treatment and deposition processes to form a high-quality passivation layer without epitaxial growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feature sizes continue to decrease to increase functional density, then production efficiency increases and costs lower, but fabrication process complexity and difficulty increase
Solution Approach 1:
The fabrication process is divided into multiple sequential steps including surface treatment, deposition of interfacial layer, oxygen scavenging layer, and barrier layer. Each step addresses specific requirements independently, making the overall complex process more manageable and controllable
Solution Approach 2:
Surface treatment is performed before deposition to prepare the substrate. The interfacial layer is deposited first to create a foundation, followed by subsequent layers. This preliminary preparation ensures better adhesion and uniformity in later steps
2Productivity
If feature sizes continue to decrease to increase functional density, then production efficiency increases and costs lower, but device reliability deteriorates
Solution Approach 1:
Multiple layers with different materials and properties are combined: interfacial layer for adhesion, oxygen scavenging layer for defect reduction, and barrier layer for protection. This composite structure addresses multiple reliability concerns simultaneously
Solution Approach 2:
The interfacial layer acts as an intermediary between the substrate and subsequent layers, improving adhesion and reducing interface defects. The oxygen scavenging layer serves as an intermediary to remove oxygen that would otherwise create defects in the final device structure
3Loss of time
If conventional deposition processes are used without epitaxial growth, then fabrication time and costs are reduced, but passivation layer quality and uniformity deteriorate
Solution Approach 1:
Deposition parameters such as temperature, pressure, and precursor flow rates are optimized to achieve uniform passivation layer formation without requiring epitaxial growth conditions. This allows faster processing while maintaining quality
Solution Approach 2:
The complex epitaxial growth process is replaced with simpler deposition processes that achieve similar or better results for passivation layer formation, reducing fabrication time and cost while maintaining uniformity
4Device complexity
If passivation layer is formed without proper surface treatment and intermediate layers, then fabrication process is simplified, but interface state density increases and device performance deteriorates
Solution Approach 1:
Surface treatment is performed first to prepare the substrate, followed by deposition of the interfacial layer before the passivation layer. This preliminary preparation ensures proper adhesion and reduces interface defects that would harm device performance
Solution Approach 2:
The interfacial layer serves as an intermediary between the substrate and passivation layer, improving adhesion and reducing interface state density. The oxygen scavenging layer acts as an intermediary to remove oxygen that would create defects at interfaces
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 approach results in enhanced device performance and reliability by improving interface state density, subthreshold swing, and drain-induced barrier lowering values, while reducing fabrication costs and time, and ensuring uniform coverage even on {111} crystal orientations.
Implementation Method 1
performing a thermal process so that the oxygen scavenging layer draws out the oxygen from a first portion of the interfacial layer adjoining the fin structure
Implementation Method 2
forming an oxygen scavenging layer over the interfacial layer
Implementation Method 3
forming an interfacial layer including an oxide containing oxygen and a semiconductor material that covers the fin structure and the isolation feature
Implementation Method 4
forming an oxygen scavenging layer over the interfacial layer
Data Source
AI summary
Structures and formation methods of a semiconductor device structure are provided. The semiconductor device structure includes a fin structure over a semiconductor substrate. An upper portion of the fin structure includes a first surface and a second surface which is inclined to the first surface. The semiconductor device structure also includes an isolation feature surrounding a lower portion of the fin structure. The semiconductor device structure further includes a passivation layer covering the first surface and the second surface of the upper portion. The passivation layer includes a semiconductor material and has a substantially uniform thickness. In addition, the semiconductor device structure includes an interfacial layer over the passivation layer. The interfacial layer includes the semiconductor material. The interfacial layer has a first portion covering the fin structure and a second portion covering the isolation feature. The passivation layer separates the fin structure from the interfacial layer.