FinFET Fabrication via Selectivity Proximity Push Process
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing FinFET devices and manufacturing methods face challenges in achieving optimal performance and complexity due to limitations in processing and manufacturing, particularly in maintaining the integrity of isolation structures and spacers during the scaling down of semiconductor integrated circuits.
Innovation Solution
A method for fabricating FinFETs involving the formation of semiconductor fins, gate stacks, spacer layers, and recesses, with a selectivity proximity push process using a remote plasma apparatus employing fluorine-containing gases and hydrogen to widen recesses and remove carbon residues, while maintaining the critical dimensions of spacers and isolation structures, and forming strained layers to enhance carrier mobility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional FinFET fabrication processes are used during scaling down, then manufacturing complexity increases, but device performance and integrity deteriorate
Solution Approach 1:
The fabrication process is divided into distinct sequential steps: forming recesses in semiconductor fins, performing selectivity proximity push process on recesses, and forming strained layers in recesses. This segmentation allows each step to be optimized independently, maintaining precision while managing complexity through structured process breakdown.
Solution Approach 2:
The selectivity proximity push process applies different treatments to different regions: fluorine-containing gas selectively etches carbon residues from recesses while hydrogen gas protects surrounding areas. This local quality approach ensures precise modification of recess regions without affecting adjacent structures, maintaining device integrity during scaling.
2Productivity
If spacer dimensions are reduced for scaling, then device density increases, but spacer integrity and isolation structure stability worsen
Solution Approach 1:
The selectivity proximity push process performs preliminary protection by using hydrogen gas to prevent oxidation of spacer materials before subsequent processing steps. This preliminary anti-action maintains spacer integrity even when dimensions are reduced for higher device density, preventing degradation that would compromise reliability.
Solution Approach 2:
The selectivity proximity push process acts as an intermediary treatment between spacer formation and final device assembly. It uses controlled gas phase reactions to clean and protect spacer surfaces without physical contact, maintaining dimensional precision and structural integrity of reduced-size spacers.
3Reliability
If aggressive etching is used to widen recesses, then carrier mobility improves, but damage to isolation structures and spacers increases
Solution Approach 1:
The selectivity proximity push process changes the chemical parameters of the etching environment by using fluorine-containing gas to selectively react with carbon residues. This parameter change enables effective cleaning and recess widening while maintaining selectivity that prevents damage to isolation structures and spacers, achieving improved carrier mobility without structural harm.
Solution Approach 2:
The process converts the potentially harmful effect of aggressive etching into a beneficial selective cleaning action. By using fluorine-containing gas that specifically targets carbon residues while sparing other materials, the process transforms what would be damaging aggressive etching into a precise cleaning mechanism that improves carrier mobility by creating cleaner recess surfaces without causing structural damage.
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 improves the performance and integrity of FinFETs by maintaining spacer dimensions, reducing oxidation, and enhancing carrier mobility through the selective etching and treatment processes, thereby addressing the complexity and scaling challenges in semiconductor manufacturing.
Implementation Method 1
a selectivity proximity push process using a remote plasma apparatus employing fluorine-containing gases
Implementation Method 2
employing fluorine-containing gases and hydrogen to widen recesses and remove carbon residues
Implementation Method 3
employing fluorine-containing gases and hydrogen to widen recesses and remove carbon residues
Implementation Method 4
forming strained layers to enhance carrier mobility
Data Source
AI summary
A method for fabricating a fin field effect transistor (FinFET) is provided. The method includes steps as follows. A gate stack is formed over a substrate having a semiconductor fin. Recesses are formed in the semiconductor fin beside the gate stack. A pre-clean process is performed to remove native oxides on surfaces of the recesses. After the pre-clean process, a selectivity proximity push process is performed using a fluorine-containing gas and a first hydrogen gas to the recesses. Strained layers are formed in the recesses.