Via Control Region Etch Rate for Semiconductor Alignment
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Solution Overview
Problem
As semiconductor device integration density increases, existing interconnection techniques face limitations in efficiently connecting active/passive elements, particularly in maintaining precise alignment and preventing abnormal expansion of via holes, which affects mass-production efficiency and reliability.
Innovation Solution
The semiconductor device incorporates via control regions with a lower etch rate than the middle insulating layer, formed using a selective densification process, to control the shape and alignment of via holes and plugs, ensuring precise connections between conductive patterns and improving manufacturing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional interconnection techniques are used, then manufacturing process is simple, but alignment precision of via holes deteriorates and abnormal expansion occurs
Solution Approach 1:
The insulating layer is segmented into two distinct regions: a via control region with higher etch rate and a surrounding region with lower etch rate. This segmentation allows differential etching behavior during via hole formation, enabling precise alignment control while preventing abnormal expansion. The via control region acts as a localized zone that guides via hole positioning without requiring complex external alignment mechanisms.
Solution Approach 2:
Different etch rate properties are assigned to different local regions of the insulating layer. The via control region possesses a locally enhanced etch rate compared to the surrounding insulating layer. This local quality differentiation enables the via holes to be precisely formed and aligned within the control region while the surrounding lower etch rate region prevents lateral expansion, achieving high precision without increasing overall device complexity.
2Reliability
If via hole size is increased to improve connection reliability, then electrical connection reliability is improved, but alignment precision deteriorates due to abnormal expansion
Solution Approach 1:
The etch rate parameter is changed locally within the via control region to enable precise via hole formation. By adjusting the etch rate of the via control region to be higher than the surrounding insulating layer, the via holes can be formed with controlled dimensions and precise alignment. The surrounding lower etch rate region then acts as a barrier that prevents abnormal lateral expansion of the via holes, maintaining both reliability and precision.
3Manufacturing precision
If multiple alignment processes are added to improve precision, then alignment precision is improved, but manufacturing efficiency deteriorates
Solution Approach 1:
The via control region is formed in advance within the insulating layer before via hole etching. This preliminary action creates a pre-defined zone with enhanced etch rate that guides subsequent via hole formation. By preparing this control structure beforehand, the patent eliminates the need for multiple alignment processes during via hole formation, achieving high precision while maintaining manufacturing efficiency through a streamlined process flow.
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 solution enhances mass-production efficiency and reliability by maintaining precise alignment and preventing abnormal expansion of via holes, thereby ensuring reliable electrical connections within the semiconductor device.
Implementation Method 1
The via control regions have a lower porosity than the middle insulating layer, resulting in a lower etch rate
Data Source
AI summary
A semiconductor device includes a lower insulating layer disposed on a substrate. A conductive pattern is formed in the lower insulating layer. A middle insulating layer is disposed on the lower insulating layer and the conductive pattern. A via control region is formed in the middle insulating layer. An upper insulating layer is disposed on the middle insulating layer and the via control region. A via plug is formed to pass through the via control region and to be connected to the conductive pattern. The via control region has a lower etch rate than the middle insulating layer.