Fin Isolation Layout for Self-Aligned Source/Drain Contacts
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Solution Overview
Problem
The challenge in semiconductor device manufacturing is to create a structure that supports both high accuracy and fast operation speed while being scaled down to smaller sizes, requiring innovative solutions for transistor design and fabrication.
Innovation Solution
The proposed integrated circuit device features a fin-type active region with a gate line intersecting it, source/drain regions, and an insulating cover, along with a fin isolation insulating unit that extends through the insulating cover, allowing for self-aligned formation of source/drain contacts and fin isolation, which helps in maintaining electrical characteristics and reliability even at high down-scaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If semiconductor devices are down-scaled to smaller sizes, then device integration density is improved, but manufacturing precision and reliability deteriorate
Solution Approach 1:
The fin isolation insulating unit is formed in advance before source/drain contact formation, establishing precise alignment references that guide subsequent processing steps. This preliminary structuring ensures that even as devices scale down, the cumulative alignment errors remain controlled because each step builds on pre-established geometric references rather than creating new alignments from scratch.
Solution Approach 2:
The fin isolation insulating unit serves dual functions: it provides electrical isolation between fins and simultaneously acts as a self-aligned reference structure for source/drain contact formation. This self-service approach eliminates the need for separate alignment processes, reducing the accumulation of alignment errors that typically worsen with device scaling.
2Area of moving object
If device size is reduced, then integration density is improved, but electrical characteristic stability deteriorates
Solution Approach 1:
The fin isolation insulating unit creates localized isolation zones with specific electrical properties around each fin structure. By tailoring the isolation characteristics locally at each fin rather than using a uniform approach, the patent maintains stable electrical characteristics even as overall device dimensions are reduced, because each local region is optimized for its specific function.
Solution Approach 2:
The fin isolation insulating unit acts as an intermediary structure between adjacent fin-type active regions, providing electrical isolation that prevents unwanted interactions. This mediator structure ensures that reducing device size does not lead to increased electrical interference between neighboring transistors, thereby maintaining reliability.
3Speed
If transistor size is reduced, then operation speed is improved, but stress concentration increases
Solution Approach 1:
The fin isolation insulating unit segments the continuous substrate into isolated fin regions, distributing mechanical stress locally around each fin rather than allowing stress to concentrate across the entire device. This segmentation approach allows transistors to be scaled down for faster operation while the isolation structures prevent stress from accumulating to damaging levels.
Data Source
AI summary
An integrated circuit device is provided as follows. A fin-type active region extends on a substrate in a first horizontal direction. A gate line extends on the fin-type active region in a second horizontal direction intersecting the first horizontal direction. A source/drain region is disposed in the fin-type active region at one side of the gate line. An insulating cover extends parallel to the substrate, with the gate line and the source/drain region arranged between the insulating cover and the substrate. A source/drain contact that vertically extends through the insulating cover has a first sidewall covered with the insulating cover and an end connected to the source/drain region. A fin isolation insulating unit vertically extends through the insulating cover into the fin-type active region. The source/drain region is arranged between the fin isolation insulating unit and the gate line.