High Temperature Hall sensors using AlGaN/GaN HEMT Structures
Abstract
Hall effect sensors are the most widely used magnetic sensors, and are commonly fabricated using narrow band-gap semiconductors such as InSb and GaAs. However, the operation of InSb and GaAs-based Hall sensors is unstable at elevated temperatures. Here, we exploited the fact that gallium nitride- (GaN) based wide band-gap (3.4eV) semiconductors have high breakdown electric field strength and are robust at elevated temperatures and tested the high temperature electrical characteristics of AlGaN/GaN heterostructure micro-Hall effect sensors with a two-dimensional electron gas (2DEG). The AlGaN/GaN heterostructures had an electron mobility of 1360 cm2/Vs and a 2DEG density of 1.0 × 1013 cm-2. The supply-current-related sensitivity (SCRS) was 77VA-1T-1 at room temperature. Notably, the temperature coefficient of the Hall voltage was +0.05 %/°C near room temperature, and SCRS was 67 VA-1T-1 at 400°C. The results for AlGaN/GaN were compared with those for AlGaAs/GaAs and AlInSb/InAsSb/AlInSb QW Hall effect sensors.
- Publication:
-
Journal of Physics Conference Series
- Pub Date:
- March 2012
- DOI:
- 10.1088/1742-6596/352/1/012009
- Bibcode:
- 2012JPhCS.352a2009K