| 摘要 |
<p>PURPOSE:To alleviate the influence of an internal stress of an a-Si:H film (i-type layer) of a device grade thereby to prevent the film from being separated or floating by laminating a buffer layer made of the a-Si:H film in which an optical band gap is specified between a substrate and the I-type layer. CONSTITUTION:A buffer layer 5 made of an a-Si:H film is interposed between a glass substrate 1 and an i-type layer 2 of a device grade. The layer 5 is formed of the nondoped a-Si:H film having 1.72eV or smaller of the value of its optical band gap (Eg<opt>). The layer 5 is obtained by holding SiH4 pressure 0.27Torr or higher at the time of forming a film by an RF glow discharging method. The internal stress of a-Si:H film having 1.72eV or smaller of an optical band gap as the layer 5 is smaller than that of the layer 2 to alleviate the influence of the internal stress. Simultaneously, since the value of the thermal expansion coefficient is near that of a glass substrate 1 as compared with the layer 2, the separation of the film due to the thermal stress scarcely occurs.</p> |
