GAA Transistor Doping Profile Tuning for Lower Channel Resistance
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Solution Overview
Problem
The semiconductor industry faces challenges in manufacturing advanced ICs due to increased complexity and power dissipation issues as device geometry decreases and functional density increases.
Innovation Solution
The method involves forming a gate all around (GAA) transistor structure with epitaxial stacks of sacrificial and channel layers, followed by ion implantation of fluorine and subsequent annealing to adjust the boron junction and reduce channel resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If geometry size is decreased to increase functional density, then production efficiency is improved and costs are lowered, but power dissipation increases
Solution Approach 1:
The patent changes the physical and chemical parameters of the semiconductor structure by implementing fluorine ion implantation followed by annealing treatment. This modifies the doping profile and material properties to reduce power dissipation while maintaining the scaled geometry, directly addressing the energy loss issue that arises from continued miniaturization
2Reliability
If ion implantation of fluorine is performed to reduce channel resistance, then drive current performance is improved, but dopant profile control becomes more challenging
Solution Approach 1:
The patent applies preliminary action by performing fluorine ion implantation before the final annealing step. This preliminary doping followed by thermal treatment allows the dopant profile to be established and then optimized, achieving precise control over the final doping distribution while ensuring good drive current performance
Solution Approach 2:
The annealing process acts as an intermediary mechanism that mediates between the ion implantation step and the final dopant profile. The thermal treatment enables controlled diffusion and redistribution of fluorine atoms, transforming the implantation damage and concentration profile into the desired final state with precise dopant distribution
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 effectively reduces channel resistance and improves drive current performance by pushing the boron junction into the Si channel, while maintaining epitaxial quality and ensuring good Vt uniformity.
Implementation Method 1
implanting fluorine ions into the source/drain epitaxial structure
Implementation Method 2
performing an annealing process to diffuse the p-type doping species into a side region of a topmost one of the channel layers
Implementation Method 3
diffuse the p-type doping species into a side region of a topmost one of the channel layers
Data Source
AI summary
A method for manufacturing a semiconductor device is provided. The method includes forming a plurality of semiconductor layers vertically stacked over a substrate, wherein the semiconductor layers are vertically spaced apart from each other; forming a source/drain epitaxial structure on sides of the semiconductor layers, wherein the source/drain epitaxial structure is doped with a p-type doping species; implanting fluorine ions into the source/drain epitaxial structure; after implanting fluorine ions into the source/drain epitaxial structure, performing an annealing process to diffuse the p-type doping species into a side region of a topmost one of the semiconductor layers; and forming a source/drain contact over the source/drain epitaxial structure.