Application research on the sensitivity of porous silicon

Applications based on sensitive property of porous silicon (PSi) were researched.As a kind of porous material,the feasibility of PSi as a getter material was studied.Five groups of samples with different parameters were prepared.The gas-sensing property of PSi was studied by the test system and suitable parameters of PSi were also discussed.Meanwhile a novel structure of humidity sensor,using porous silicon as humidity-sensitive material,based on MEMS process has been successfully designed.The humidity-sensing properties were studied by a test system.Because of the polysilicon layer deposited upon the PSi layer,the humidity sensor can realize a quick dehumidification by itself.To extend service life and reduce the effect of the environment,a passivation layer (Si3N4) was also deposited on the surface of electrodes.The result indicated the novel humidity sensor presented high sensitivity (1.1 pF/RH％),low hysteresis,low temperature coefficient (0.5％RH/℃) and high stability.