| 摘要 |
PURPOSE:To decrease the number of processes to a large extent, by simultaneously implanting ions in a first resistor group and a second resistor group, omitting the separate ion implantations, and finishing an annealing process by one time. CONSTITUTION:An insulating film 3 is formed on a semiconductor substrate 2. Then a polysilicon film 4, which is to become a first resistor group 5, is formed on the insulating film 3. Thereafter, the polysilicon film 4 and the insulating film 3 are patterned by a photoetching method. Therefore the polysilicon becomes a selective ion implantation mask. A semiconductor substrate 2 is exposed. The first resistor group 5 is isolated by the insulating film 3 and ions are implanted in the gaps in the first resistor group 5. Thus a second resistor group 6 is formed. The semiconductor substrate 2, in which ions are implanted, undergoes thermal oxidation, and a silicon oxide film 7 is formed on the surface of the semiconductor substrate 2. Therefore the silicon oxide films 3 and 7 are formed as a unitary body on the surface of the semiconductor substrate 2. Finally, electrodes 9 are connected to parts, which are to become contact holes 8 of the first resistor group 5 and the second resistor group 6. |
