Semiconductor Contact Structure with Oxide Interlayer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices become smaller, the contact resistance at the interface between the source/drain contact and the epitaxial region significantly affects electrical properties, necessitating reduced contact resistance to enhance device performance.
Innovation Solution
A semiconductor structure is developed with an oxide-containing or metal oxide-containing layer formed between the epitaxial region and the contact structure, which lowers the Schottky barrier height and reduces contact resistance by incorporating a phosphorus-rich epitaxial region and forming the oxide layer during the contact hole etching process, along with a silicide layer to further enhance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If device size is reduced to increase functional device density, then device integration is improved, but contact resistance at the source/drain interface becomes more significant and worsens electrical properties
Solution Approach 1:
An oxide-containing layer is introduced as an intermediary between the contact structure and the epitaxial region. This intermediate layer modifies the interface properties to reduce contact resistance, allowing small device dimensions to maintain good electrical contact. The oxide-containing layer acts as a mediator that facilitates charge transport across the contact interface.
Solution Approach 2:
The Schottky barrier height at the contact interface is modified by changing the chemical composition and structure of the interface layer. By forming an oxide-containing layer with specific properties, the energy barrier for charge transport is reduced, thereby decreasing contact resistance while maintaining scaled device dimensions.
2Reliability
If contact resistance is reduced by modifying interface structure, then electrical properties are improved, but device structure becomes more complex
Solution Approach 1:
The oxide-containing layer is formed by combining existing process steps, specifically by utilizing the contact hole etching process to simultaneously create the contact opening and form the oxide-containing layer through in-situ oxidation. This merging of steps reduces process complexity while achieving the desired interface modification.
Solution Approach 2:
The oxide-containing layer is formed in advance during the contact hole etching process before the contact structure is deposited. This preliminary formation of the modified interface layer ensures optimal contact properties are established before subsequent processing steps, simplifying the overall fabrication sequence.
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 solution effectively reduces contact resistance by up to 64.4% and improves device performance by lowering the Schottky barrier height, thereby addressing the challenge of increasing device complexity and performance requirements.
Implementation Method 1
the oxide-containing layer and/or the metal oxide-containing layer is formed between the epitaxial region and the contact structure for lowering the Schottky barrier height between the layers of the stacked structure
Data Source
AI summary
A manufacturing method of a semiconductor structure includes the following steps. An epitaxial region is formed in a semiconductor substrate. A dielectric layer is formed on the epitaxial region, and a contact hole is formed in the dielectric layer. The contact hole exposes a part of the epitaxial region, and an oxide-containing layer is formed on the epitaxial region exposed by the contact hole. A contact structure is formed in the contact hole and on the oxide-containing layer. The oxide-containing layer is located between the contact structure and the epitaxial region. A semiconductor structure includes the semiconductor substrate, at least one epitaxial region, the contact structure, the oxide-containing layer, and a silicide layer. The contact structure is disposed on the epitaxial region. The oxide-containing layer is disposed between the epitaxial region and the contact structure. The silicide layer is disposed between the oxide-containing layer and the contact structure.