Three-dimensional doping and diffusion in nano scaled devices as studied by atom probe tomography.

Area of Science:

• Semiconductor device physics
• Materials science

Background:

• Advanced nano-scale devices (FinFETs, TFETs) demand precise 3D doping control.
• Gate overlap and doping conformality are critical for device performance.

Purpose of the Study:

• To investigate 3D doping, diffusion, and activation in silicon FinFETs.
• To correlate plasma doping process details with dopant profiles and device performance.

Main Methods:

• Utilized atom probe tomography (APT) for atomic-resolution 3D dopant distribution analysis.
• Employed self-regulatory plasma doping (SRPD) for device fabrication.
• Performed statistical analysis of dopant atom distributions.

Main Results:

• Determined dopant conformality and spatial extent after SRPD.
• Demonstrated annealing-dependent 3D doping profiles and gate overlap.
• Observed concentration-dependent 3D diffusion with anisotropic gradients.
• Identified dopant clustering in high-concentration regions.

Conclusions:

• Plasma doping process details critically influence 3D doping profiles and device performance.
• Concentration-dependent diffusion impacts dopant distribution differently in vertical and lateral directions.
• Dopant clustering correlates with activation and affects device performance.