| 摘要 |
PURPOSE:To enable to use a polycrystalline silicon film as a variable resistor having a certain fixed variation breadth in a semiconductor integrated circuit device by a method wherein an electrode is formed on the polycrystalline silicon film interposing an insulating film between them, and electric field is applied to the electrode thereof. CONSTITUTION:An arsenic buried layer 3 of 2.0mum depth is formed selectively on a silicon substrate 1, then an epitaxial layer 2 and an insulatingly isolating oxide film 4 are formed thereon, and after then, a collector diffusion layer 5 diffused with phosphorus is formed. Then boron ions are implanted, pressed in and diffused to form a base diffusion layer 6, and after then, arsenic ions are implanted, pressed in and diffused to form an emitter diffusion layer 7. After then, the polycrystalline silicon film 8 implanted with boron ions is formed on the insulatingly isolating oxide film, and is oxidized. After then, contact holes 10 are opened selectively, and aluminum electrodes 9 are formed selectively. |
