Auxiliary Silicon Nitride Contact Layer for Narrow Hole Reliability
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Solution Overview
Problem
Shrinking device geometries in semiconductor devices poses challenges in meeting demands on electric characteristics such as contact resistance and latch-up robustness, particularly in narrow contact holes.
Innovation Solution
Formation of an auxiliary layer composed of silicon and nitrogen on the semiconductor structure, followed by deposition of a conductive material like AlSiCu, AlSi, or tungsten, which prevents silicon regrowth and ensures low-resistive electrical connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If device geometries are shrunk to reduce costs and increase device functionalities per unit area, then productivity and area efficiency are improved, but contact resistance and latch-up robustness deteriorate
Solution Approach 1:
A silicon nitride auxiliary layer is introduced as an intermediary between the semiconductor structure and the conductive filling material. This auxiliary layer prevents silicon regrowth into the contact hole, thereby maintaining low contact resistance and improving latch-up robustness while allowing the use of shrunk device geometries.
Solution Approach 2:
The silicon nitride auxiliary layer is formed in advance before depositing the conductive filling material. This preliminary action prevents silicon regrowth from occurring during subsequent processing steps, ensuring that the contact hole remains clear for proper electrical connection.
2Ease of manufacture
If device geometries are shrunk, then manufacturing cost is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The silicon nitride auxiliary layer serves as a protective intermediary that lines the contact hole walls. This layer provides a defined interface that helps control the dimensional precision of the contact hole, ensuring consistent electrical properties even as overall device dimensions are reduced.
3Device complexity
If conductive filling material is deposited directly on the semiconductor structure, then manufacturing process is simplified, but silicon regrowth occurs causing increased contact resistance
Solution Approach 1:
The silicon nitride auxiliary layer is deposited as an intermediary layer between the semiconductor structure and the conductive filling material. This auxiliary layer acts as a barrier that prevents silicon regrowth from reaching the conductive material, thereby maintaining low contact resistance without significantly complicating the manufacturing process.
Solution Approach 2:
The structure employs a composite arrangement combining silicon nitride (auxiliary layer) with conductive materials (such as tungsten, copper, or aluminum alloys). This composite structure prevents silicon regrowth while maintaining excellent electrical conductivity, resolving the conflict between process simplicity and electrical performance.
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
Improves contact resistance and latch-up robustness by preventing silicon regrowth in narrow contact holes, thereby enhancing the performance of semiconductor devices.
Implementation Method 1
The auxiliary layer prevents silicon regrowth in narrow contact holes
Implementation Method 2
The conductive material is electrically connected to the part of the semiconductor structure via the auxiliary layer
Data Source
AI summary
A method of forming a semiconductor device is proposed. The method includes providing a semiconductor structure. The method further includes forming an auxiliary layer directly on a part of the semiconductor structure. Silicon and nitrogen are main components of the auxiliary layer. The method further includes forming a conductive material on the auxiliary layer. The conductive material incudes AlSiCu, AlSi or tungsten, and is electrically connected to the part of the semiconductor structure via the auxiliary layer.