Towards wafer scale inductive characterization of spin transfer torque critical current density of magnetic tunnel junction stacks

TL;DR

This paper investigates wafer-scale inductive methods to measure the critical current density for spin transfer torque switching in magnetic tunnel junctions, aiming to enable large-scale, non-destructive characterization.

Contribution

It demonstrates the feasibility of wafer-scale inductive probing to determine critical current density, aligning with traditional methods and paving the way for wafer-level metrology.

Findings

Inductive measurements match current-induced switching results.

Effective damping and magnetostatic parameters are derived from inductive data.

Potential for wafer probe station based metrology of $j^{c0}$.

Abstract

We explore the prospects of wafer scale inductive probing of the critical current density $j^{c0}$ for spin transfer torque switching of a CoFeB/MgO/CoFeB magnetic tunnel junction with varying MgO thickness. From inductive measurements magnetostatic parameters and the effective damping are derived and $j^{c0}$ is calculated based on spin transfer torque equations. The inductive values compare well to the values derived from current induced switching measurements on individual nanopillars. Using a wafer scale inductive probe head could in the future enable wafer probe station based metrology of $j^{c0}$.