Large area shower implanter for thin film transistors

Using a 30 cm diameter RIPE ion source, a large area low energy ion shower implanter has been developed for low cost TFT fabrication. The beam current density uniformity is +or-3.5% over the centre 20 cm diameter. With magnetic field of 200 Gauss and RF power of 450 W, the extracted ion current density at 3*10/sup -4/ mbar hydrogen pressure and 3 KV screen voltage was 100 mu A/cm/sup 2/. For 3 KeV and five minute phosphorus implantation, dose and projected range are 2.48*10/sup 16/ cm/sup -2/ and 83 AA, respectively. The fine rectifier characteristics of implanted diodes show that this shower implanter is suitable for TFT contact layer formation.<
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