POLYSILICON TFTS FABRICATED AT LOW-TEMPERATURE USING ION DOPING SELF-ACTIVATION TECHNIQUE

Crystallization phenomenon induced by ion beam irradiation at low temp erature(less than 350-degrees-C)using large area ion implantation with out mass selection (Ion doping technique) have been investigated. Both phosphorus ions and proton were simultaneously implanted into poly-si licon layers. Above 4x10(15) ions/cm2 dose of proton, amorphous silico n changes into poly-crystalline phase. The crystallization was found t o occur simultaneously with phosphorus doping and to depend on an amou nt of the irradiation of proton beam. This technique enables us to eli minate the annealing process for an activation of implanted dopant. Th e field-effect mobilities of fabricated n-channel and p-channel poly-S i TFTs were 60cm2/V.s and 29cm2/V.S respectively.