Inclined Gate Structure for Multi-Gate Transistor Isolation
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Solution Overview
Problem
Current semiconductor devices face challenges in scaling and integration due to limitations in gate structure design and channel formation, which affect the density and performance of multi-gate transistors, particularly in maintaining effective current control and suppressing short channel effects.
Innovation Solution
The semiconductor device incorporates a substrate with active patterns, field insulating films, and gate structures that include inclined surfaces and device isolation films, allowing for the formation of separation trenches and improved gate structure alignment, enhancing integration and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional gate structures are used in multi-gate transistors, then manufacturing is simpler, but current control effectiveness deteriorates and short channel effects increase
Solution Approach 1:
The gate structure employs inclined side walls with specific angle ranges (30-60 degrees) instead of vertical walls, creating a curved/angled geometry that improves electrostatic control over the channel. This curvature allows the gate electric field to extend more effectively into the channel region, suppressing short channel effects while maintaining manufacturability through standard etching processes.
Solution Approach 2:
The invention transitions from a planar gate structure to a three-dimensional structure with inclined side walls and multi-layer construction. By adding the dimensional aspect of angled侧 walls and multiple gate layers, the gate achieves superior control over the channel in vertical and lateral directions simultaneously, improving current control without requiring excessive miniaturization.
2Productivity
If gate length is reduced to increase density, then device integration improves, but short channel effects worsen
Solution Approach 1:
The inclined side walls with angles of 30-60 degrees create a geometric configuration that extends the gate's electrostatic influence deeper into the channel. This curved geometry compensates for reduced gate length by improving the electric field distribution, allowing effective short channel effect suppression even as gate dimensions are scaled down for higher density.
Solution Approach 2:
The gate structure utilizes multi-layer construction with different materials having complementary properties. The combination of various dielectric and conductive layers creates a composite gate that achieves superior electrostatic control at smaller dimensions, enabling high integration density while maintaining reliability through material optimization rather than relying solely on dimensional scaling.
3Reliability
If multi-layer gate structures are formed, then current control improves, but manufacturing complexity increases
Solution Approach 1:
The fabrication process employs preliminary patterning steps where mandrel structures and spacer layers are formed before the final gate electrode deposition. These preliminary structures guide subsequent processing steps, enabling precise formation of inclined side walls and multi-layer gates through sequential deposition and etching operations, thereby managing manufacturing complexity through staged fabrication.
Solution Approach 2:
The invention introduces intermediate spacer layers and mandrel structures that serve as temporary guides during fabrication. These intermediary elements enable the formation of complex inclined gate geometries by providing self-aligned reference structures, reducing the need for complex lithographic alignment and simplifying the overall manufacturing process despite the multi-layer gate complexity.
Data Source
AI summary
A semiconductor device and a method for fabricating the same, the device including an active pattern extending in a first direction on a substrate; a field insulating film surrounding a part of the active pattern; a first gate structure extending in a second direction on the active pattern and the field insulating film, a second gate structure spaced apart from the first gate structure and extending in the second direction on the active pattern and the field insulating film; and a first device isolation film between the first and second gate structure, wherein a side wall of the first gate structure facing the first device isolation film includes an inclined surface having an acute angle with respect to an upper surface of the active pattern, and a lowermost surface of the first device isolation film is lower than or substantially coplanar with an uppermost surface of the field insulating film.