基于纳米多晶硅薄膜晶体管磁传感器制作工艺和特性

A magnetic field sensor based on nano-polysilicon thin films transistors（TFTs） with Hall probes is proposed.The magnetic field sensors are fabricated on <100> orientation high resistivity（ρ>500Ω·cm） silicon substrates by using CMOS technology,which adopt nano-polysilicon thin films with thicknesses of 90 nm and heterojunction interfaces between the nano-polysilicon thin films and the high resistivity silicon substrates as the sensing layers.The experimental results show that when V_DS = 5.0 V,the magnetic sensitivities of magnetic field sensors based on nano-polysilicon TFTs with length-width ratios of 160μm/80μm,320μm/80μm and 480μm/80μm are 78 mV/T,55 mV/T and 34 mV/T,respectively.Under the same conditions,the magnetic sensitivity of the obtained magnetic field sensor is significantly improved in comparison with a Hall magnetic field sensor adopting silicon as the sensing layers.