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The surface properties of a plastic substrate were changed using a novel surface treatment called atomic hydrogen annealing (AHA). In this method, a plastic substrate was exposed to atomic hydrogen generated by cracking hydrogen molecules on heated tungsten wire. Surface roughness was increased, and O atoms and halogen elements (F and Cl) were selectively etched by AHA. The surface modification of the PEN substrate affects the surface property of the SiN<sub>x</sub> film. Adhesion between the SiN<sub>x</sub> film and the PEN substrate in the SiN<sub>x</sub> film/PEN substrate prepared by Cat-CVD shows excellent properties.

  A novel low-temperature crystallization method is proposed; the excimer laser annealing (ELA) of amorphous silicon (a-Si) with a hydrogen-modulation-doped layer (ELHMD). The effects of hydrogen on low-energy crystallization by conventional ELA and ELHMD were investigated. As the hydrogen concentration increases, the crystallinity of the polycrystalline silicon (poly-Si) prepared at a low energy density improves. It is considered that the nucleation is enhanced by the desorption energy of hydrogen from the Si-H<sub>2</sub> bond during the Si melting. In addition, the film exfoliation by H<sub>2</sub> burst can be suppressed using HMD a-Si film.<br>

a-Si薄膜のエキシマ・レーザ結晶化において膜中の水素原子が核形成とその後の粒成長,更には,二次元結晶成長に大きな影響を及ぼす事を初めて見出した.核形成に関しては水素変調ドープ層を持つa-Si薄膜のエキシマ・レーザ結晶化(ELHMD; Excimer Laser Annealing of Hydrogen Modulation Doped a-Si Film)により核形成位置を制御でき高品質化を図れる.粒成長に関しては,二次元結晶粒径の寸法により,粒内,又は粒界の水素原子が粒界移動に影響を与える.

アクティブマトリックス型有機発光ダイオード(AM-OLED, active matrix-organic light emitting diode)ディスプレイの画素駆動回路において,従来型薄膜トランジスタ(TFT, thin film tranisitor)をダブルSOI (DSOI, double silicon on insulator)上に形成されたトンネル誘電体トランジスタ(TDTFT, tunneling dielectric TFT)で置き換えた構造に対して,従来型の画素回路を仮定して,ゲートしきい値電圧のばらつきとOLED出力電流の関係を調べた.ソース・ドレーン両端部に0.5nm厚のTiO_2膜の作製を仮定することにより,TDTFTはしきい値電圧の変動によるOLED出力電流の変化を低減できることが明らかになった.理由は,DSOI構造によるゲートしきい値の低下,更に,トンネル抵抗の減少と電子移動度低下の阻止による.更に,TDTFTは従来型TFTに比較してオフ電流の値も減少させることができ,DSOI上に形成されたTDTFTは次世代フラットパネルディスプレイに用いられる新しいデバイスの候補としての可能性を秘めている.

Silicon nitride (SiN_x) films were deposited on Si substrates at 80℃ by using a catalytic chemical vapor deposition (Cat-CVD) technique to investigate the optimal deposition condition. SiH_4 flow rate was varied from 6 to 18 sccm. It is shown that the stress, Young's modulus, fracture toughness and film composition strongly depend on SiH_4 flow rate. These changes of film properties are related to the gases desorption from growing surface. The amount of the gases desorption reaction depends on deposition rate, that is, the rate of the Si-H insertion reaction. The desorption of hydrogen and ammonia gases from growing surface causes the shrinkage of the film surface, which generates tensile stress. Also, SiN_x films with high hydrogen contents show low stress, low Young's modulus and high fracture toughness.