| 摘要 |
PURPOSE:To fill a hole at a high speed, by selectively depositing a poly Si layer on the side surface of a contact hole by utilizing anisotropic etching, and making the deposition of tungsten to progress on the side surface of the hole. CONSTITUTION:An SiO2 layer 2 is deposited on an Si layer 1, and a hole 4 is provided. A thin SiO2 layer 3 is formed by slight oxidation after the hole 4 is formed. A poly Si layer 5 is deposited. When the layer 5 is etched by RIE, the RIE advances only in the approximately vertical direction. Therefore, poly Si 5' remains at a step part, whose thickness in the vertical direction is large. Then slightly excessive etching is performed so that the upper end of the poly Si wall is recommendably lower than the upper end of the hole. The entire surface is slightly etched and the thin SiO2 layer at the bottom part is removed. Thereafter, tungsten 6 is deposited by CVD. At this time the deposition of the tungsten progresses on both the bottom and side surfaces of the hole. Therefore the hole part is quickly filled, but the tungsten is not deposited on the SiO2 layer 2.
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