FinFET Protection Layer for Ion Implantation Damage
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Solution Overview
Problem
Conventional techniques for doping the fin channel of FinFETs often result in damage to the fin channel and gate dielectric layer, impacting the performance and reliability of the transistor due to defects formed during the ion implantation process.
Innovation Solution
A protection layer is formed over the fin-like channel of FinFETs before doping, extending along the sidewalls and overlaying the top surface, which minimizes damage during the doping process and also provides protection during the dummy gate removal process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If ion implantation process is used to dope the fin channel, then the doping concentration can be controlled, but the fin channel and gate dielectric layer are damaged
Solution Approach 1:
A protection layer is introduced as an intermediary between the ion implantation process and the fin channel/gate dielectric layer. This protection layer absorbs the impact of energized dopants, preventing direct damage to the fin channel and gate dielectric layer while still allowing controlled doping to occur.
Solution Approach 2:
The protection layer is formed in advance before the ion implantation process. This preliminary action prepares the structure to withstand the upcoming doping process, ensuring that when energized dopants are introduced, the vulnerable fin channel and gate dielectric layer are already shielded.
2Quantity of substance
If higher energy level is used for ion implantation, then the doping concentration increases, but the damage to fin channel and gate dielectric layer increases
Solution Approach 1:
The protection layer serves as a mediator that allows high-energy ion implantation to proceed while intercepting the harmful effects. It absorbs the kinetic energy of incoming dopants, preventing them from causing excessive damage to the underlying structures.
Solution Approach 2:
The protection layer provides beforehand cushioning by being positioned between the ion source and the vulnerable structures. It cushions the impact of high-energy dopants, reducing the harmful effects before they reach the fin channel and gate dielectric layer.
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 protection layer effectively prevents damage to the fin channel and gate dielectric layer, enhancing the overall performance and reliability of the FinFET by maintaining the integrity of these critical components.
Implementation Method 1
the ion implantation process includes bombarding plural dopants that are energized at that particular energy level on the fin channel so as to implant the dopants into the fin channel
Data Source
AI summary
A fin-based transistor and method for making same. In some embodiments, the transistor includes a first fin and a second fin formed on a substrate, the first and second fins being laterally spaced from each other, wherein an upper portion of the first fin is doped with a first type of dopant and an upper portion of the second fin is doped with a second type of dopant different from the first type of dopant; a protection layer formed over the first and second fins, wherein the protection layer comprises a dielectric material selected from a group comprising: silicon nitride, silicon oxynitride, and a combination thereof; and source and drain features formed in respective side portions of the first and second fins.