Junction defects of self-aligned, excimer-laser-annealed poly-Si TFTs

Reports residual ion implantation damage at source/drain junctions of self-aligned, excimer-laser-annealed poly-Si TFTs. TEM observation revealed that the implantation damage was not completely annealed at the junction by excimer laser annealing because the laser irradiation intensity decreased remarkably at the junction due to diffraction of laser beam at gate electrode edge. Field effect mobility of poly-Si TFTs was degraded by the crystalline defects at the junction particularly for short channel devices. We eliminated the junction defects by oblique-incidence excimer laser annealing and improved the characteristics of poly-Si TFTs.