High quality SiO 2 gate insulators are one of the key technologies for improving performance of Low Temperature Poly Silicon TFTs. We have developed an ALD/PECVD reactor, which handles 370 mm 470 mm glass substrates. The reactor has a unique plasma source of the monopole antenna, which is the electromagnetic wave coupled type and operates at VHF range. A PE-ALD SiO 2 film was deposited at 200 with alternating exposures of aminosilane and radical oxygen generated by the plasma. Growth rate of the film and thickness variation were 0.1 nm cycle -1 and less than 5 %, respectively. Conformal film growth was observed on patterned substrates. Uniform current-voltage performance was confirmed on the glass and its electrical field was higher than 8.0 MVcm -1 at a leakage current of 1×10 -6 Acm -2 . The film had an excellent Si / SiO 2 interface trap density of lower than 1×10 11 cm -2 eV -1 after forming gas annealing.

A high quality gate insulator is one of the key technologies for improving the performance of Low Temperature Poly Silicon TFTs. We propose an all-new stacked gate insulator, which is prepared with ALD technology for an interfacial layer, and a monopole antenna Plasma Enhanced Chemical Vapor Deposition (PECVD) technology for a secondary layer. The ALD/PECVD reactor, which handles glass substrates of 370 mm×470 mm in size was developed, and its performance was evaluated. Silicon dioxide films were deposited at 400℃ with the reactor. Thickness variations of the ALD film and the PECVD film were confirmed to be less than ±5% and ±10%, respectively. The stacked insulator, which was composed of the 2nm-ALD film and the 100nm-PECVD film, had an excellent Si/SiO 2 interface of 1×10 11 cm -2 eV -1 and breakdown electrical field of 7.5 MVcm -1 .

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