| 摘要 |
PURPOSE:To obtain a thin-film transistor having an optical shielding effect without increasing photoetching processes by constituting an a-Si thin-film layer as a semiconductor layer of an undoped a-Si thin-film and a B light-doped a-Si thin-film. CONSTITUTION:A gate electrode 22 is formed onto a substrate 21, and a gate insulating film 23 is shaped onto the gate electrode. A first semiconductor region 24 consisting of a-Si and a second semiconductor film 25 composed of B light- doped a-Si are formed onto the gate insulating film. The quantity of B doped is such that diborane is brought to 10<4> or less to silane regarding a reaction-gas flow ratio at the time of film formation. A drain electrode 26 is shaped at one end of the thin-film 24 and a source electrode 27 at the other end. Consequently, the thin-film 25 functions as an optical shielding film, and prevents the collision of visible rays with the thin-film 24. Accordingly, a malfunction in which currents flow between the electrodes 26 and 27 by the incidence of beams to the thin-film 24 is obviated. |
