| 摘要 |
PURPOSE:To eliminate a step portion in an area where a contact hole is not opened, by depositing a secondary interlayer insulator onto a first interlayer insulator having a portion that resembles a step shape in a device so that the step portion is covered smoothly, and moreover carrying out etching for each layer. CONSTITUTION:An oxide film 4 is deposited as a first interlayer insulator on a silicon substrate 1 by use of the reduced pressure chemical vapor deposition(CVD) method after a device including a polysilicon 2 and an oxide film 3 is formed on the silicon substrate 1. As a secondary interlayer insulator, a borophosphosilicateglass(BPSG) film 5 is deposited by use of the atmospheric pressure CVD method so that a step portion on the surface is covered smoothly, and then a mask pattern is formed with a photoresist 6. First etching is carried out in a reaction chamber with mixed gas containing CF4 and O2. Secondary etching is carried out in the same reaction chamber with mixed gas containing CF4 and hydrogen to obtain a contact hole formed in a self-aligned way in a recess located at the step portion. |
