| 摘要 |
PURPOSE:To enable to accurately form a thick oxide layer on the bottom of a groove by oxidizing a semiconductor substrate with an anti-oxidative mask formed by anisotropic etching in a self-aligning manner in the groove. CONSTITUTION:A silicon substrate is used as a semiconductor substrate 1, and a silicon dioxide layer 2 and a silicon nitride layer 3 of the first anti- oxidative layer are sequentially coated thereon. Then, a groove 4 is formed on the substrate 1 through the layers 3, 2. With the Si3N4 layer remaining on the substrate 1 as a mask it is oxidized in a dry oxygen, an SiO2 layer 5 is formed in the grove 4, and an Si2N4 layer is coated as the second anti- oxidative layer on the groove 4. The layer 6 of the bottom of the groove 4 is removed, opened and with the opened layer 6 as a mask the substrate 1 is oxidized in wet O2, and an SiO2 layer 7 is formed as a semiconductor oxide layer on the bottom of the groove. Thus, a device can be microminiaturized. |
