| 摘要 |
<p>PURPOSE:To obtain an element structure of a channel etching system TFT in which an a-Si:H semiconductor layer is as thin as a channel protection type TFT by using a material having a higher etching rate than the etching rate of a-Si:H as a material of a contact layer. CONSTITUTION:An Al2O3 oxidized film 3 is formed on a gate electrode 2 formed on a substrate 1 and thereafter, an Si3N4 film, the a-Si:H semiconductor layer and an n<+>/a-SiGe layer are continuously formed by a plasma CVD method. The three layers discribed above are worked to an island shape by photoetching, by which a gate insulating layer 4 and semiconductor layer 5 are formed. A vapor deposited Cr layer and an N<+>/a-SiGe layer are photoetched to form a contact layer 6 and source/drain electrode 7 thereon. The etching rate of the n<+>/a-SiGe is about 10 times the etching rate of the a-Si:H layer and, therefore, the etching amt. of the a-Si:H semiconductor layer is reduced to 1/10 if the n<+>/a-SiGe is used as the contact layer.</p> |
