Gate-All-Around Gate Stack With TiSiN Barrier for Threshold Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor devices face challenges in enhancing operating characteristics, particularly in scaling and suppressing short channel effects, while maintaining effective current control and threshold voltage adjustment.
Innovation Solution
The semiconductor device incorporates a gate-all-around structure with a work function adjustment pattern featuring titanium silicon nitride (TiSiN) barrier films and aluminum-based work function adjustment films, which help in preventing metal diffusion and adjusting threshold voltage, thereby improving transistor performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a gate-all-around structure with nanowire-shaped silicon body is used for scaling, then device density and current control capability are improved, but short channel effects become more difficult to suppress and manufacturing precision requirements increase
Solution Approach 1:
The gate structure completely surrounds the nanowire channel in a nested configuration, with the gate insulating film and gate electrode wrapping around the silicon body. This three-dimensional gate-all-around structure provides superior electrostatic control over the channel, enabling effective suppression of short channel effects while maintaining high device density through efficient scaling.
Solution Approach 2:
The gate structure employs composite materials including the gate insulating film and gate electrode made from multiple materials with different properties. This composite approach allows optimization of both electrostatic control for short channel effect suppression and electrical characteristics for current control, resolving the contradiction between density improvement and reliability maintenance.
2Manufacturing precision
If the work function adjustment pattern uses thin films to improve manufacturing precision, then device scaling is enhanced, but metal diffusion control becomes more difficult
Solution Approach 1:
A barrier film is introduced as an intermediary layer between the work function adjustment film and the gate insulating film. This barrier film acts as a diffusion barrier that prevents metal atoms from migrating into the gate insulating film, thereby controlling metal diffusion harmful effects while allowing the use of thin work function adjustment films for improved manufacturing precision and device scaling.
3Reliability
If aluminum-based work function adjustment films are used to adjust threshold voltage, then device performance is improved, but metal diffusion into the gate insulating film increases
Solution Approach 1:
The barrier film serves as a protective intermediary layer that enables the use of aluminum-based work function adjustment films for effective threshold voltage adjustment while preventing aluminum diffusion into the gate insulating film. This resolves the contradiction by allowing the beneficial electrical properties of aluminum to be utilized without the harmful diffusion effects.
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 configuration enhances the operating characteristics of transistors by effectively controlling current and suppressing short channel effects, while allowing for precise threshold voltage adjustment, even with thin films and close sheet pattern spacing.
Implementation Method 1
a barrier film including titanium silicon nitride (TiSiN)... The barrier film prevents metal diffusion into the gate insulating film
Data Source
AI summary
A semiconductor device includes an active pattern disposed on a substrate. A gate insulating film is disposed on the active pattern and extends along the active pattern. A work function adjustment pattern is disposed on the gate insulating film and extends along the gate insulating film. A gate electrode is disposed on the work function adjustment pattern. The work function adjustment pattern includes a first work function adjustment film, a second work function adjustment film that includes aluminum and wraps the first work function adjustment film, and a barrier film including titanium silicon nitride (TiSiN). A silicon concentration of the barrier film is in a range of about 30 at % or less.