Gate Replacement Process for High Temperature Annealing
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Solution Overview
Problem
Conventional gate replacement processes in semiconductor IC manufacturing are limited by the low thermal budget of silicide features, which restricts the flexibility in metal gate work function tuning and threshold voltage adjustment due to high temperature processing constraints.
Innovation Solution
Implementing a gate replacement process before forming silicide features, allowing for high temperature annealing to adjust the work function and threshold voltage of the gate structure, while forming contact features through a contact opening after the gate replacement process to avoid damaging the silicide regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If high temperature annealing process is performed for gate replacement, then work function tuning flexibility is improved, but silicide features are damaged
Solution Approach 1:
The gate replacement process including high temperature annealing is performed before forming the silicide contact features. This preliminary action allows the gate structure to undergo work function tuning without the risk of damaging pre-formed silicide regions, as the silicide features are created only after the thermal budget is exhausted
Solution Approach 2:
The conventional sequence is inverted: instead of forming silicide features first and then performing gate replacement, the gate replacement is performed first followed by silicide feature formation. This inversion resolves the thermal budget conflict by reversing the process order
2Temperature
If gate replacement process is performed before forming contact features, then thermal budget for annealing is increased, but process sequence complexity increases
Solution Approach 1:
The gate replacement process is performed as a preliminary action before contact feature formation. This allows the utilization of the full thermal budget for annealing processes without concern for damaging subsequently formed silicide contact features
Solution Approach 2:
The process sequence parameter is changed from conventional (silicide first, then gate replacement) to inverted (gate replacement first, then silicide). This parameter change enables higher annealing temperatures to be applied during gate replacement without compromising contact feature integrity
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 increases the thermal budget for annealing processes, enabling more flexible work function tuning and threshold voltage adjustment of the gate structure without damaging the silicide features, thereby expanding the processing window for gate replacement.
Implementation Method 1
performing a gate replacement process to form a gate structure, wherein the gate replacement process includes an annealing process
Implementation Method 2
performing a high temperature annealing process to adjust a threshold voltage of the metal gate
Data Source
AI summary
A method for fabricating an integrated circuit device is disclosed. An exemplary method comprises performing a gate replacement process to form a gate structure, wherein the gate replacement process includes an annealing process; after the annealing process, removing portions of a dielectric material layer to form a contact opening, wherein a portion of the substrate is exposed; forming a silicide feature on the exposed portion of the substrate through the contact opening; and filling the contact opening to form a contact to the exposed portion of the substrate.