Summary: | 碩士 === 國立交通大學 === 光電(科學)研究所 === 83 === Magnetic field sensors which exploit the galvanomagnetic ef-
fect due to the Lorentz force on charge carriers have been
pres- ent for many years.In this study,magnetic field sensors
of two structures have been implemented and optimized in order
to inve- stigate the possibility of increasing the symmetry of
device se- nsitivities in three directions for 3-D magnetic-
field sensors. For Hall voltage output format,the p+ well of
the second struct- ure incteases the sensitivities in x-,y- and
z-directions and improve the symmtry of sensitivities.For
differential current output format,the p+ well can only
increase the sensitivities for an in-plane magnetic-field
applied. To improve the magnetic responses to magnetic field
perpendicular to the , wafer surface ,Co-Ni coating is used and
the sensitivities for a magnetic field applied perpendicularly
to the wafer surface are ten times more than that of a uncoated
device.Further,a 2-drain have been implemented for TFT magnetic
field sensors. Experimental results for this type of sensors
indicate that there is a maximum value of sensitivity for
various gate voltage.
|