Characteristics of cross-sectional atom probe analysis on semiconductor structures.

Area of Science:

• Materials Science
• Metrology
• Semiconductor Physics

Background:

• Next-generation semiconductor technologies demand metrology tools with sub-nanometer spatial resolution.
• Laser-assisted Atom Probe (LAP) is a potential technique for analyzing 3D semiconductor structures like FinFETs.

Purpose of the Study:

• To assess the lateral resolution of LAP for silicon/silicon-germanium multilayer structures.
• To investigate laser-induced distortions and their impact on metrology accuracy.

Main Methods:

• Experimental analysis of a silicon/silicon-germanium multilayer structure using LAP.
• Evaluation of lateral resolution and quantification errors.

Main Results:

• Laser-sample interactions cause surface distortions, leading to transient dimensional errors.
• Degradation of lateral resolution was observed, with measurements ranging from 1-1.8 nm/decade.
• Current data reconstruction methods result in significant quantification errors for heterogeneous structures.

Conclusions:

• The applicability of LAP for quantitative analysis of heterogeneous semiconductor structures is limited by reconstruction errors.
• Accurate results require advanced reconstruction algorithms that account for time-dependent tip shape dynamics.