Magnetic random access memory (MRAM) is a versatile nonvolatile memory capable of replacing SRAM, DRAM and Flash memory. For example MRAM has been introduced as a low-power cache memory for high performance CPU’s. The key component in an MRAM cell is the magnetic tunnel junction (MTJ) consisting of a tunnel barrier stacked between many metallic and magnetic layers with thicknesses down to 1 nm. Monitoring the electromagnetic performance of this stack is important as fabrication yield is highly dependent on adverse effects like pinholes. The current-in-plane tunneling (CIPT) method has for more than a decade been a reliable metrology in quickly accessing the key parameters of an MTJ, i.e. the resistance area product and the tunneling magnetoresistance. The CIPT method is similar to a transmission line measurement performed with movable microelectrodes to access the transfer length of the magnetic tunnel junction. This presentation will discuss recent innovations in the CIPT method, including advanced data analysis to boost precision on blanket films, adaptation to small test pads and vibration tolerant microelectrodes.
Dirch Hjorth Petersen was born in Denmark in 1979. He received the M.Sc. and Ph.D. degrees in applied physics from the Technical University of Denmark (DTU) in 2006 and 2010, respectively. He is currently leader of the Nanomaterials Metrology group at DTU Nanotech. His research interests include methods for electrical characterization of ultrathin electronic materials as well as electronic materials used in CMOS and memory production.