Breakthrough in current-in-plane tunneling measurement precision by application of multi-variable fitting algorithm

Area of Science:

• Materials Science
• Electrical Engineering
• Condensed Matter Physics

Background:

• Micro-four-point probe (M4PP) metrology is essential for characterizing thin film materials.
• Current-in-plane tunneling (CIPT) is a key technique for evaluating magnetic tunnel junction (MTJ) stacks used in magnetic random-access memories (MRAM).
• Existing M4PP methods face limitations in precision and reproducibility due to electrode placement inaccuracies.

Purpose of the Study:

• To introduce an advanced electrode position correction methodology for M4PP metrology.
• To enhance the precision and reproducibility of transmission line (transfer length) type measurements.
• To specifically apply and validate this correction technique for the M4PP current-in-plane tunneling (CIPT) method.

Main Methods:

• Development and application of advanced electrode position correction algorithms.
• Implementation of the corrected M4PP methodology on the CIPT technique.
• Experimental validation using two distinct magnetic tunnel junction (MTJ) stacks.

Main Results:

• Achieved significant improvements in measurement precision for resistance-area product and tunneling magnetoresistance.
• Demonstrated enhanced measurement reproducibility, with improvements up to a factor of 17.
• Validated the effectiveness of the advanced position correction technique on MTJ stacks.

Conclusions:

• The advanced electrode position correction technique offers a substantial breakthrough in M4PP metrology.
• This methodology significantly enhances the precision and reproducibility of CIPT measurements for MTJ characterization.
• The improved metrology is crucial for the continued development of advanced magnetic random-access memory technologies.