Copper Electrode Barrier Layer for Semiconductor Interconnects
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Solution Overview
Problem
The increasing demand for smaller, lighter communication devices necessitates semiconductor devices and electrode-connecting structures with finer pitches, gaps, thicknesses, and volumes, which existing technologies struggle to achieve effectively, particularly in ensuring reliable electrical connections and preventing contamination from insulating layers.
Innovation Solution
The development of electrode-connecting structures and semiconductor devices with copper (Cu) metal electrodes, where copper-containing electrodes are not in direct contact with insulating layers, and instead, electrode barrier layers are interposed to create a low-resistance connection while preventing oxygen or impurity contamination, using configurations such as lower and upper electrode structures with specific width relationships and barrier layer arrangements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If copper electrodes are placed in direct contact with insulating layers, then manufacturing process is simplified, but oxygen or impurity contamination occurs degrading electrical properties
Solution Approach 1:
An electrode barrier layer is introduced as an intermediary between the copper electrode and the insulating layer. This barrier layer prevents oxygen and impurity contamination from the insulating layer while maintaining electrical connection, thus resolving the contradiction between manufacturing simplicity and connection reliability.
2Length of stationary object
If electrode structures are made thinner to reduce device thickness, then device thickness is reduced, but alignment precision between upper and lower electrodes becomes more difficult to maintain
Solution Approach 1:
The electrode barrier layer extends in the horizontal dimension beyond the copper electrode boundaries, creating an overlapping region with the upper electrode barrier layer. This dimensional extension provides alignment tolerance, allowing thinner electrodes while maintaining manufacturing precision through the extended barrier layer coverage.
3Reliability
If copper electrodes are used to reduce resistance, then electrical conductivity is improved, but contamination from insulating layers degrades the copper properties
Solution Approach 1:
The electrode barrier layer serves as a protective intermediary that physically separates the copper electrode from the insulating layer, preventing oxygen and impurity contamination while allowing the copper to maintain its low-resistance electrical conductivity properties.
Solution Approach 2:
The potential harmful effect of the insulating layer (oxygen release and contamination) is converted into a beneficial protective function by the barrier layer, which prevents the harmful oxygen from reaching the copper electrode while maintaining the overall device structure.
4Manufacturing precision
If electrode barrier layers are extended beyond electrode boundaries, then alignment tolerance is improved, but device complexity increases
Solution Approach 1:
The electrode barrier layer performs multiple functions: it prevents contamination, provides electrical isolation, and extends beyond electrode boundaries to provide alignment tolerance. This multi-functionality reduces the need for additional separate structures, thereby managing device complexity while improving alignment precision.
Data Source
AI summary
Provided are electrode-connecting structures or semiconductor devices, including a lower device including a lower substrate, a lower insulating layer formed on the lower substrate, and a lower electrode structure formed in the lower insulating layer, wherein the lower electrode structure includes a lower electrode barrier layer and a lower metal electrode formed on the lower electrode barrier layer, and an upper device including an upper substrate, an upper insulating layer formed under the upper substrate, and an upper electrode structure formed in the upper insulating layer, wherein the upper electrode structure includes an upper electrode barrier layer extending from the inside of the upper insulating layer under a bottom surface thereof and an upper metal electrode formed on the upper electrode barrier layer. The lower metal electrode is in direct contact with the upper metal electrode.