Crystallized Gate Dielectric Structure for Etch Loss Reduction
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Solution Overview
Problem
As semiconductor devices continue to shrink in size, the etching of gate dielectric layers during the formation of transistor structures leads to significant losses, affecting the performance of the resulting devices.
Innovation Solution
Implementing a crystallization process to decrease the etch rate of gate dielectric layers, which are used as etch stop layers during the patterning of work function tuning layers, thereby reducing losses and improving the performance of the devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If gate dielectric layers are etched during work function tuning layer patterning, then the work function tuning layers can be patterned, but significant losses of gate dielectric layers occur
Solution Approach 1:
A crystallization process is performed on the gate dielectric layer before etching to transform it from amorphous to crystalline state. This preliminary action modifies the physical properties of the gate dielectric layer, making it more resistant to subsequent etching processes while allowing the work function tuning layer patterning to proceed.
Solution Approach 2:
The crystallization process changes the physical state and structural parameters of the gate dielectric layer. By altering the material's crystalline structure, its etch resistance is enhanced, reducing material loss during the patterning of work function tuning layers while maintaining the necessary etching selectivity.
2Productivity
If the etch rate of gate dielectric layers is high, then etching processes are faster, but losses of gate dielectric layers increase significantly
Solution Approach 1:
The gate dielectric layer undergoes crystallization that modifies its physical parameters, specifically reducing its etch rate. This parameter change allows the layer to be more resistant to etching, thereby reducing material loss while maintaining controlled etching speeds for the patterning process.
Solution Approach 2:
The crystallization treatment is applied as a preliminary step before etching. This pre-treatment prepares the gate dielectric layer to have reduced etch susceptibility, enabling the subsequent etching process to proceed with minimal material loss while maintaining adequate processing speed.
3Ease of manufacture
If amorphous gate dielectric layers are used, then deposition is simpler, but etching selectivity is reduced leading to greater losses
Solution Approach 1:
The gate dielectric layer is transformed from amorphous to crystalline state through a crystallization process. This parameter change in the material's structural state enhances its etching selectivity and resistance, improving reliability during patterning operations while the initial amorphous deposition remains simple.
Solution Approach 2:
A crystallization step is introduced as a preliminary treatment after simple amorphous deposition. This preliminary action converts the easily deposited amorphous material into a crystalline form that exhibits superior etching selectivity, combining the advantages of both simple deposition and high etching resistance.
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
The crystallization process enhances the etching selectivity of gate dielectric layers, minimizing losses during etching and improving the overall performance of semiconductor devices.
Implementation Method 1
a crystallization process is performed to decrease the etch rate of the gate dielectric layers
Data Source
AI summary
In an embodiment, a device includes: a first gate dielectric on a first channel region of a first semiconductor feature; a first gate electrode on the first gate dielectric; a second gate dielectric on a second channel region of a second semiconductor feature, the second gate dielectric having a greater crystallinity than the first gate dielectric; and a second gate electrode on the second gate dielectric.