Slow- and rapid-scan frequency-swept electrically detected magnetic resonance of MOSFETs with a non-resonant microwave probe within a semiconductor wafer-probing station

Abstract

We report on a novel electron paramagnetic resonance (EPR) technique that merges electrically detected magnetic resonance (EDMR) with a conventional semiconductor wafer probing station. This union, which we refer to as wafer-level EDMR (WL- EDMR), allows EDMR measurements to be performed on an unaltered, fully processed semiconductor wafer. Our measurements replace the conventional EPR microwave cavity or resonator with a very small non-resonant near-field microwave probe. Bipolar amplification effect, spin dependent charge pumping, and spatially resolved EDMR are demonstrated on various planar 4H-silicon carbide metal-oxide-semiconductor field-effect transistor (4H-SiC MOSFET) structures. 4H-SiC is a wide bandgap semiconductor and the leading polytype for high-temperature and high-power MOSFET applications. These measurements are made via both “rapid scan” frequency-swept EDMR and “slow scan” frequency swept EDMR. The elimination of the resonance cavity and incorporation with a wafer probing station greatly simplifies the EDMR detection scheme and offers promise for widespread EDMR adoption in semiconductor reliability laboratories.

Wafer-Level near Zero Field Spin Dependent Charge Pumping: Effects of Nitrogen on 4H-SiC MOSFETs

“…Consequently, we present a new technique called near zero field spin dependent charge pumping (NZF SDCP) which can extract similar information as EPR and EDMR without the need for a large electromagnet or complicated microwave system. As such, this technique is uniquely positioned for very simple integration within a wafer probe station, similar to the work of McCrory et al who built and demonstrated a wafer-level EDMR spectrometer [7]. Their work paves the way for wafer-level EDMR measurements in high throughput environments.…”

“…For the case of a traditional EDMR spectrometer, the oscillating magnetic field is introduced via microwaves in a resonance cavity or an RF coil. For the case of the wafer-level system, they are introduced via a small, fragile shorted coaxial probe (probe wire diameter 50 µm) [7]. The NZF measurement does not involve an oscillating magnetic field, thus does not require microwave or RF peripherals.…”

EPR Everywhere

“…Transition metal spectra have been recorded at higher fields using two different stepwise direct detection methods: field-stepped direct detection (FSDD) at the University of Denver [ 74 ] and non-adiabatic rapid-scan (NARS) at the Medical College of Wisconsin [ 90 , 91 ] and would be even easier to apply to narrow spectra at low magnetic fields, if required at all. Additionally, RS has been performed via frequency sweeps using a static magnetic field, shifting the RS capabilities from the coil driver to the frequency generator [ 92 , 93 ]. This technique is particularly enticing for low-field applications where high-resolution frequency sweeps may be possible with the current generation of commercially available arbitrary waveform generators (AWGs) and in non-resonant applications where considerations of bandwidth in relation to resonator Q are no longer necessary [ 94 ].…”

Electrically Detected Magnetic Resonance on a Chip (EDMRoC) for Analysis of Thin-Film Silicon Photovoltaics

“…Similarly, the available driving microwave field also becomes very small (typically π/2 pulse lengths become as long as 2 µs) to the point that coherence experiments are no longer possible, especially in the case of silicon solar cells [11]. Recently, EDMR experiments have been successfully demonstrated by replacing the resonator with a non-resonant antenna [12,13], indicating the possibility to generate a microwave (B 1 ) field amplitude of ≈0.1-0.12 mT at 9 GHz to detect the EDMR signal in a-Si:H samples [12], and to measure the frequency-swept and rapid scan EDMR [13].…”