Manufacture of trench capacitor

Abstract

Abstract PURPOSE:To form a trench having an excellent shape simply, and to improve cell characteristics by removing a partial silicon oxide-film pattern, using a resist pattern as a mask to shape the trench and forming a dielectric film and an electrode into a capacitor region including the trench. CONSTITUTION:An silicon oxide film 12 is shaped onto an silicon substrate 11, and a pattern is formed through selective etching. An silicate glass film 13 is shaped onto the side wall of the pattern of the silicon oxide film 12. Single crystal silicon layers 14 containing a P-type impurity are epitaxial-grown selectively, employing the pattern of the silicon oxide film 12 as a mask. N-type diffusion layers 15 are shaped at the same time as the epitaxial growth of the layers 14. The silicon oxide films 12 and the silicate glass films 13 are removed selectively, thus shaping trenches 17. The ions of phosphorus or arsenic are implanted to form diffusion layers 18 even in regions except the side walls of the trenches 17. A resist pattern 16 is removed, a dielectric film 19 as a capacitor is shaped, a polycrystalline silicon film 20 to which an impurity is doped is deposited, the trenches are buried, and the polycrystalline silicon film 20 is flattened. Lastly, the polycrystalline silicon film 20 is patterned, thus forming a capacitor electrode.

Inventors

• 👤 Fumio Kiyozumi
• 👤 清住　文雄
• 👤 Yoshiaki Katakura
• 👤 片倉　義明

Bibliographic Details