| 摘要 |
PURPOSE: A method for forming an insulating layer is provided to reduce a dielectric constant of an intermetal dielectric layer by directly forming an inorganic spin-on-glass layer on a lower interconnection line without interposing a buffer layer. CONSTITUTION: The method includes depositing an oxide layer(22) on a semiconductor substrate(21) where devices are formed, then forming a metal layer thereon, then forming the lower interconnection line(23) by selectively etching the metal layer, then forming the inorganic spin-on-glass layer(24) over a resultant structure, and then forming a silicon-rich oxide layer(25) on the inorganic spin-on-glass layer(24). The inorganic spin-on-glass layer(24) to be used as the intermetal dielectric layer is directly formed on the interconnection line(23) without any buffer layer, and the silicon-rich oxide layer(25) protects the inorganic spin-on-glass layer(24) from external harmful moisture and ions. The silicon-rich oxide layer(25) is deposited to about 3000Å by plasma enhanced chemical vapor deposition employing a reaction gas of silane(SiH4), oxygen(O2), or nitrogen oxide(N2O). In addition, the silicon-rich oxide layer(25) has a ratio of oxygen to silicon ranging from 1.2 to 1.6.
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