| 摘要 |
PURPOSE:To improve the integration and the performance by improving the controllability and the miniaturization by a method wherein the first layer formed on a substrate with surface irregularities is anisotropically etched to leave the first layer on side walls further, leaving the second layer on the side walls by the same etching process. CONSTITUTION:N-type buried layers 22 are formed on a P-type single crystal silicon substrate 21 to grow an epitaxially grown layer 23 and then an element isolating region 25 is formed by thermooxidizing a specified pattern. At this time, an emitter region and a base region are formed in element regions 24; polycrystalline silicon layer 26 as a conductor layer is formed on overall surface of both regions; overall surface of the layer 26 is coated with an oxide film 27; and after patterning together with the layer 26, overall surface is coated with another oxide film 29. The first side walls 30 are formed by anisotropically etching the oxide film 29. Later overall surface is coated with the other oxide film 31 to be removed by anisotropical ion etching process to form the second side walls 32 lying upon the first side walls 30. At this time, the second side walls 32 can be formed with excellent controllability just like the formation of the first side walls 30. |
