DRAM with capacitor structure - has semiconductor substrate and doped region of opposite conductivity and insulating layer on substrate surface with aperture reaching to doped layer

摘要

There is a lower capacitor electrode (11) with a first section (11a) in contact with a surface of the doped layer, and a surface of the insulating layer (7). The second electrode section (11b) extends along the outer edge of the first electrode section and orthogonally to the semiconductor substrate (1) main surface. The second section of the lower capacitor electrode has a round end and a side surface of roughness of up to 200 angstrom. The surface of the lower electrode is covered by a capacitor insulating layer (12). A top capacitor electrode (13) covers the surface of the insulating layer. ADVANTAGE - Increased service life of the capacitor insulating layer, and smooth surface of electrode section.