Interconnection Structure With Boron Oxide Etch Stop for Short Prevention
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Solution Overview
Problem
The challenge of preventing undesirable electrical shorts between contact structures and adjacent conductive structures becomes more complex as device geometries shrink, particularly when multiple exposure and etch processes are employed to form contact features in integrated semiconductor devices.
Innovation Solution
The use of a first etch stop layer, composed of boron-based and oxygen-rich boron oxide layers, provides etch selectivity and adhesion to dielectric materials, preventing electrical shorts by controlling the etching process and ensuring precise formation of contact structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple exposure and etch processes are employed to form contact features, then device density and functionality increase, but the risk of electrical shorts between contact structures and adjacent conductive structures increases
Solution Approach 1:
A dedicated etch stop layer is introduced as an intermediary between the dielectric material and the contact structure. This layer serves as a protective mediator that prevents direct contact and potential electrical shorts between the conductive contact structure and adjacent conductive structures during multi-step etching processes, while still allowing the contact structure to be formed through the dielectric material.
Solution Approach 2:
The etch stop layer is formed in advance before the contact structures are created. This preliminary action establishes a protective barrier prior to the multiple exposure and etch processes, ensuring that even as subsequent etching steps are performed to increase device functionality, the risk of electrical shorts is already mitigated by the pre-existing etch stop layer.
2Quantity of substance
If device dimensions are reduced to increase density, then more elements can be integrated, but the precision required to prevent electrical shorts becomes more difficult to achieve
Solution Approach 1:
The etch stop layer acts as a precisely controllable intermediary that is easier to form with high precision than contact structures at reduced dimensions. By dedicating a separate layer specifically for etch stopping, the manufacturing precision requirement is shifted from the contact structure formation process to the etch stop layer formation, which can be achieved through standardized deposition techniques.
Solution Approach 2:
The structure is segmented into distinct functional layers: the dielectric material, the etch stop layer, and the contact structure. This segmentation allows each layer to be optimized independently - the etch stop layer can be uniformly deposited with precise thickness control, while the contact structures can be formed with the required precision for electrical connections, thereby managing the overall manufacturing precision challenge.
3Manufacturing precision
If etch selectivity is enhanced to improve contact structure formation, then manufacturing precision improves, but process complexity increases
Solution Approach 1:
The etch stop layer serves as a dedicated intermediary that provides etch selectivity in a controlled manner. Rather than attempting to achieve complex etch selectivity through multiple etching parameters and conditions, the selectivity is simplified by introducing a material layer specifically designed to stop the etch process, thereby improving contact structure precision while managing process complexity.
Solution Approach 2:
The etch stop layer enables control of the etching process through material composition parameters rather than complex process parameters. By selecting materials with appropriate etch rate differences, the etch stop layer provides predictable and controllable etch termination, achieving manufacturing precision through material parameter selection rather than complex process parameter optimization.
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
This approach enhances the reliability of contact structures by reducing electrical shorts, ensuring precise etching and improving the integrity of semiconductor device interconnections.
Implementation Method 1
forming a first etch stop layer over the first dielectric material, which includes forming a boron-containing layer and forming an oxygen-rich boron oxide layer on the boron-containing layer
Implementation Method 2
forming an oxygen-rich boron oxide layer on the boron-containing layer... provides etch selectivity and adhesion to dielectric materials
Data Source
AI summary
A method for forming an interconnection structure is provided. The method includes forming a first conductive feature in a first dielectric material, forming an etch stop layer over the first dielectric material, which includes forming a boron-containing layer, and forming an oxygen-rich boron oxide layer on the boron-containing layer. The method also includes forming a second dielectric material over the etch stop layer, forming an opening through the second dielectric material and the etch stop layer to expose a top surface of the first conductive feature, and forming a second conductive feature in the opening.