This paper reports two novel sensing modes for the 3axis Hall-effect sensor based on an inverted pyramid structure. The proposed current-spinning schemes enable 3-axis magnetic field measurements with reduced readout complexity (6 less switching phases for 3D1) while preserving sensitivity and offset. Residual offsets in the millitesla range at 1 V supply voltage were measured on three identical samples using 6 - or 12 -phase current spinning sequences, with in-plane voltage and currentrelated sensitivities up to 16.7 mV/ V/ T and 86.1 V/ A/ T, respectively. These modes represent a more efficient and simpler readout method for the pyramid sensor, while remaining competitive with the state-of-the-art.

Microelectronic magnetic sensors are essential in diverse applications, including automotive, industrial, and consumer electronics. Hall-effect devices hold the largest share of the magnetic sensor market, and they are particularly valued for their reliability, low cost and CMOS compatibility. This paper introduces a novel 3-axis Hall-effect sensor element based on an inverted pyramid structure, realized by leveraging MEMS micromachining and CMOS processing. The devices are manufactured by etching the pyramid openings with TMAH and implanting the sloped walls with n-dopants to define the active area. Through the use of various bias-sense detection modes, the device is able to detect both in-plane and out-of-plane magnetic fields within a single compact structure. In addition, the offset can be significantly reduced by one to three orders of magnitude by employing the current-spinning method. The device presented in this work demonstrated high in-plane and out-of-plane current- and voltage-related sensitivities ranging between 64.1 to 198 V A⁻¹ T⁻¹ and 14.8 to 21.4 mV V⁻¹ T⁻¹, with crosstalk below 4.7%. The sensor exhibits a thermal noise floor which corresponds to approximately 0.5μT/Hz at 1.31 V supply. This novel Hall-effect sensor represents a promising and simpler alternative to existing state-of-the-art 3-axis magnetic sensors, offering a viable solution for precise and reliable magnetic field sensing in various applications such as position feedback and power monitoring. (Figure presented.)

We present iron-doped beta gallium oxide (Fe-ßGa2O3) as a candidate for photoconductive semiconductor switches (PCSSs) with sub-bandgap light. From a commercially available Fe-ßGa2O3 wafer, we first did material characterization. This included measurements of absorption coefficient and dopant composition, carrier activation energy up to 200 C, break down field of planar electrodes (limited from material passivation), and free carrier recombination lifetime, and thermal effects up to 203 C on photocurrent with a 447 nm light emitting diode (LED) source. We then demonstrated pulsed operation of a Fe-ßGa2O3 PCSS under different sub-bandgap wavelengths (355, 532, and 1064 nm) and sub-ns pulses. Fe-ßGa2O3 is a candidate for high temperature PCSS with 355 nm responsivity of 7 × 10-7 A-cm/W-kV at room temperature and up to 5.5 × 10-4 A-cm/W-kV at 200 C. From these investigations, we discuss a simple trap model to describe the illumination process of the PCSS. Fe-ßGa2O3 has a high breakdown field and has moderate responsivity characteristics, but the dark current at high temperature leads to low photo-to-dark current ratio (PDCR). Regardless, we verify its potential as a PCSS material for harsh environment applications.

This article provides an overview of power semiconductor devices (PSDs) for the distributed energy resource (DER) system. To begin with, an overview of electrically triggered silicon carbide (SiC) and gallium nitride (GaN) devices followed by a brief narration of ultrawide bandgap (UWBG) PSDs and, subsequently, an overview of optically activated PSDs encompassing photoconductive semiconductor switch (PCSS) and optical bipolar PSDs are provided. Finally, an overview of PSD packaging and reliability is captured.

In this work, we demonstrate and model the deep-level defect physics of semi-insulating gallium arsenide bulk photoconductive semiconductor switches (PCSS) with gap size of 10 μ and 25 μ in dark-mode operation. Experimental measurements up to biasing field of 10 kV/cm show near-bistable characteristics in the dark-mode current-voltage relations for the PCSS, which cannot be reproduced through commercial Technology Computer-Aided Design simulations. Thus, we model the PCSS by solving for homogeneous non-equilibrium steady-state of the PCSS trap dynamics, where we introduce two semi-Analytical models both involving two deep levels with impact ionization effects. Both models have an excited deep-level that can capture electrons from or emit electrons to the conduction band. The two models differ, however, by the fact that one has a ground state with capture and emission, whereas the other does not include such mechanisms but instead includes electron excitation and relaxation processes directly between the ground state and the excited state without interactions with the conduction band. We find that the former does not fit with experimental near-bistable features while the latter achieves a good match with the same total number of fitting parameters. Further measurements of bias upto 50 kV/cm on one 10 μ PCSS confirms the validity of the second model as well. Finally, a brief discussion of the implications on the illuminated operation of the PCSS is also given to illustrate the importance of including defect interactions and defect avalanche effects.