Micron scale Quantum Well Hall Effect integrated sensor arrays for magnetic domain imaging


High sensitivity 16×1 integrated sensor array with various sensor activate area from 2 μm x 2 μm to 50 μm x 50 μm have been designed and fabricated for magnetic domain measurements (see figure 1). With various sensor pitch length, a maximum horizontal spatial resolution of 1270 Pixels Per Inch (PPI) can be achieved. These Quantum Well Hall Effect (QWHE) [1] sensor arrays have been directly bonded onto special PCB carriers with support analogue circuits. The use of Two-dimensional Electron Gas (2DEG) channel in the sensor design, allows for high electron mobility and high carrier concentration leading to high sensor sensitivity and low thermal noise. With the use of signal mixing and up conversion techniques to avoid flicker noise (1/f noise), a minimum magnetic field of 20 nT can be measured. Furthermore, a high precision 2D X-Y stage has been designed to be used with these QWHE integrated sensor array for 2-dimenstional magnetic domain imaging measurements.