Indium-tin oxide/Si contacts with In- and Sn-diffusion barriers in polycrystalline Si thin-film transistor liquid-crystal displays

Indium and tin were used as the diffusion barrier between indium-tin oxide (ITO) and polycrystalline-silicon layers to reduce the contact resistance. The ITO/Si contacts may be adopted in thin-film transistor liquid-crystal displays (TFT-LCD) to reduce the number of fabrication steps. With In and Sn layers, contact-resistance values of 5 x 10(-3) - 4 x 10(-3) Omegacm(2) were obtained. These values were higher than those of the conventional ITO/Mo/Al/Si contacts (3 x 10(-5) - 4 x 10(-4) Omegacm(2)) but lower than the values obtained from ITO/Si contacts (about 1 x 10(-2) Omegacm(2)). The Sn was stable after annealing, but In diffused into Si and lost its function as the diffusion barrier.