Integrated 3D magnetometer and its fabrication process – MAGIE.pdf

More and more general public mobile devices such as watches, mobile phone, GPS include an electronic compass to find their orientation in space. They provide advanced navigation capabilities, for example to indicate the direction in which a person or a vehicle is moving when GPS is not available, or for emerging smart location-based services. The 3D magnetometers market is now rapidly growing and there is a current need for smaller, more sensitive and energy-saving magnetic sensors. However present technologies which are based on high sensitivity magnetoresistive sensors do not allow the fabrication of fully integrated 3D magnetometers: a three axis magnetometer can only be fabricated using a hybrid scheme composed of at least two non-coplanar substrates. This leads to fragile and bulky devices with high manufacturing cost and a sensitivity limited by systematic errors due to the manufacturing procedure. In addition, these magnetoresistive sensors suffer from the need for a compensation of their intrinsic thermal drift.

We recently registered a patent for a 3D magnetometer offering innovating solution to these problems. In this magnetometer, the three components of the magnetic field are simultaneously deduced by magnetoresistive sensors integrated on the same substrate. Since the sensors are all strictly identical with the same sensitivity and thermal drift, they significantly simplify the drift compensation. This type of sensor thus offers higher compactness and sensitivity combined with reduced consumption and a much simpler manufacturing process. Our invention should allow for a decrease of the manufacturing cost and a reduced power consumption of the three axial compass and will be easily inserted into a mobile device to be used as an integrated low power micro-compass.

This project is divided into three different tasks: 1/ a market survey to define the magnetometer technological specifications and to protect the intellectual property; 2/ the technological development for the sensor fabrication; 3/ the material development and the tests; in particular this last task includes the optimisation of the sensor to reach the desired sensitivity, the characterisation of the noise, spatial sensitivity and thermal drift. This project implies two partners, Spintec laboratory, responsible for the technological development, the materials optimisation and the test, and FIST-SA, which is a private company specialised in transfer and commercialisation of innovating technologies, who will be responsible for the market survey and for finding opportunities for technology transfer to companies.