Transistor Gate Isolation Structure for Void-Induced Short Prevention
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Solution Overview
Problem
As semiconductor devices, such as FinFETs, undergo miniaturization, the reduction in feature size leads to issues like seam or void formation in gate structures, which can result in conductive material deposition and shorting of source/drain regions, compromising device reliability.
Innovation Solution
The gate structure is divided into multiple gate structures by forming an isolation structure that extends through the gate, patterning an opening, filling it with a dielectric material, and treating it to shrink any seams or voids, reducing the risk of conductive material deposition during subsequent processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the gate structure is miniaturized to improve integration density, then more components can be integrated into a given area, but seams or voids form in the gate structure which can lead to conductive material deposition and shorting of source/drain regions
Solution Approach 1:
The gate structure is divided into multiple segments by forming isolation structures that extend through the gate, separating it into discrete sections. This segmentation prevents continuous conductive paths through seams or voids while maintaining the miniaturized form factor needed for high integration density.
Solution Approach 2:
Dielectric material is introduced as an intermediary substance within openings formed through the gate structure. This dielectric material fills and seals seams or voids, acting as a barrier that prevents conductive material deposition and shorting between source/drain regions, thereby maintaining gate structure integrity at miniaturized dimensions.
2Reliability
If the gate structure is divided into multiple gate structures by forming an isolation structure, then the reliability is improved by reducing shorting risk, but the device complexity increases
Solution Approach 1:
The isolation structure formation process is merged with existing gate patterning steps, where the same lithography and etching processes used to define gate structures are also used to form the isolation structures. This combining of operations adds minimal process steps while achieving both reliability improvement and complexity management.
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 semiconductor devices by minimizing the risk of shorting and improving the integrity of the gate structure, leading to more reliable and efficient device performance.
Implementation Method 1
treating the dielectric material shrinks (i.e., reduces the width and/or height of) any seams or voids that may be in the isolation structure
Data Source
AI summary
Transistor gate isolation structures and methods of forming the same are provided. In an embodiment, a device includes: an isolation region; a first gate structure on the isolation region; a second gate structure on the isolation region; and a gate isolation structure between the first gate structure and the second gate structure in a first cross-section, an upper portion of the gate isolation structure having a first concentration of an element, a lower portion of the gate isolation structure having a second concentration of the element, the first concentration different from the second concentration, the lower portion extending continuously along a sidewall of the first gate structure, beneath the upper portion, and along a sidewall of the second gate structure.