| 摘要 |
PURPOSE:To reduce the mutual action among the devices by forming a layer having good conductivity under the electrically active layer. CONSTITUTION:The silicon substrate which has high impurity concentration necessary for forming a well-conductive layer required by the device design is formed. The surface of this substrate is subjected to mirror polishing and further cleaning and then it is placed on a substrate supporting table. Next, the substrate supporting table is inserted into an electric oven and is heated after reducing the pressure by evacuation. If the temperature reaches the predetermined value, that temperature is maintained till the profile of impurity concentration required by the device design is attained. The the temperature is lowered and the silicon substrate is took out. By control of temperature and time for the heat treatment, a well-conductive layer is formed under the active layer and it becomes possible to fabricate the silicon substrate of high integration which makes no maloperation. |
