The modeling and fabrication of a magnetic microsensor based on a magneto-transistor were presented. The magnetic sensor is fabricated by the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process without any post-process. The finite element method (FEM) software Sentaurus TCAD is utilized to analyze the electrical properties and carriers motion path of the magneto-transistor. A readout circuit is used to amplify the voltage difference of the bases into the output voltage. Experiments show that the sensitivity of the magnetic sensor is 354 mV/T at the supply current of 4 mA.

Featured Application: Three-axis magnetic field microsensors in this study can be applied to various electronic instruments, portable electronic devices, mobile phones, and industrial equipment.Abstract: This study develops a three-axis magnetic field (MF) microsensor manufactured by a complementary metal oxide semiconductor (CMOS) process. The MF microsensor contains a ring emitter, four bases, and eight collectors. Sentaurus TCAD was used to simulate the microsensor characterization. The STI (shallow trench isolation) oxide in the process was used to limit the current direction and reduce leakage current. The microsensor produces a voltage difference once it senses a magnetic field. An amplifier circuitry magnifies voltage difference into a voltage output. Experiments reveals that the MF microsensor has a sensitivity of 1.45 V/T along the x-axis and a sensitivity of 1.37 V/T along the y-axis.

Gynaecomastia is common in infancy and adolescent boys, but other inciting causes should be kept in mind and necessitate further evaluation should be conducted to determine any underlying conditions. A 22-year-old unmarried male adolescent visited our endocrinology clinic for feminine appearance despite operations for bilateral gynaecomastia 4 years ago. Physical examination showed inverted triangular distribution of pubic hair, sparse beard, small-sized testes, flaccid short penis and surgical scar of the chest wall. Serum hormones study revealed primary hypergonadotropic hypogonadism, and cytogenetic study disclosed female complement (46, XX). The authors recommend that sexual chromosome abnormality should be considered in patients with hypogonadism to avert androgen deficiency-related complications early and that long-term team care should be provided to improve the patient's health-related quality of life.