# Analysis and Optimization of Vertical NPN BJT for Strong Magnetic Fields

## TL;DR

This paper studies how strong magnetic fields affect vertical NPN bipolar transistors and proposes a design to improve their performance in such environments.

## Contribution

The paper proposes a novel interference-resistant design for BJT transistors in strong magnetic fields.

## Key findings

- Magnetic fields alter carrier distribution and current transport paths in vertical NPN BJTs.
- The asymmetry of BJT structures leads to magnetic anisotropy effects.
- The proposed design improves device stability in complex magnetic environments.

## Abstract

This study systematically investigates the electrical characteristics of the vertical NPN bipolar junction transistor (VNPN BJT) in the strong magnetic field environment, focusing on analyzing the effects of magnetic field direction and intensity on key parameters such as terminal current and current gain (β). The simulation results show that the magnetic field induces changes in the carrier distribution, thereby affecting the current transport path. Through the in-depth analysis of electron motion trajectories, potential distribution, and Hall voltage, this paper reveals the physical mechanisms behind the device’s characteristic changes under the magnetic field and discovers that the inherent asymmetry of the BJT structure induces significant magnetic anisotropy effects. On this basis, a design for interference-resistant structures in strong magnetic field environments is proposed, effectively suppressing the adverse effects of magnetic-field-sensitive directions on BJT performance and significantly improving the device’s stability in complex magnetic field environments.