| 摘要 |
PURPOSE:To increase the memory capacity by a method wherein a plurality grooves is provided in a semiconductor substrate surface along a charge transfer direction and transfer electrodes are built on the groove upper ends, sides, and bottoms for the construction of a transfer channel along a corrugated geometry. CONSTITUTION:On the surface of a semiconductor substrate 9, a gate oxide film 10 and nitride film 11 are formed, protrusion lines are formed of many a photoresist 12 along the direction D of charge transfer, and then a silicon oxide film 10a is formed. Grooves 13 of a depth L are formed by anisotropic etching. Next, an impurity layer 14, silicon oxide film 15, and polycrystalline layer 16 are formed. Only a polycrystalline silicon layer 16a is retained after anisotropic etching and, on its surface, an oxide film 17 is formed. Next, a polycrystalline silicon layer 18 and oxide film 19 are formed. A clock signal is applied to a group of four polycrystalline silicon layers 16a, 18, 16a, 18, for the formation of a transfer channel in the impurity layer 14. With two polycrystalline silicon layers 16a being formed vertically on a flat surface, integration may be enhanced.
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