| 摘要 |
PURPOSE:To obtain a resistor having low capacitance for fine integrated circuits by etching a silicon nitride film with a high selection ratio on the resistor composed of polycrystalline silicon. CONSTITUTION:A silicon oxide film 2 is formed, on a silicon substrate 1 on which polycrystalline silicon is evaporated, and then the film 2 is subjected to etching to form a polycrystalline layer 4. A silicon nitride film 8 is evaporated on the layer 4 to perform high selection dry etching of Si3N4 using gas of which ratio of F to H is about 2 or less such as CH2F2 or CH3F and so forth as a reactive gas. The SiO2 and a polycrystalline Si are hardly etched. The width of a resistor body 4 is determined by a mask which cuts the polycrystalline silicon and the length of the resistor body 4 is determined by a mask which cuts the silicon nitride film 8. It is not necessary to put both the masks together accurately. Since a contact surface between a metal electrode 6 and the polycrystalline silicon layer 4 is large, the resistor having small contact resistance can be formed. |
