Trench capacitor configuration and method of producing it

A trench capacitor configuration, comprising:

• a substrate formed with a trench, said trench having an upper region and a lower region and defining a side wall in said substrate;
• an insulating collar formed in said upper region;
• a buried well disposed in said substrate, said lower region at least partly extending through said buried well;
• a buried plate formed around said lower region and serving as an outer capacitor electrode;
• a dielectric layer lining said lower region and said insulating collar, said dielectric layer serving as a capacitor dielectric;
• a conductive trench filling disposed in said trench;
• and
• a conductive-contact layer of tungsten nitride disposed, between said substrate and said conductive trench filling, in said trench above said insulating collar, said conductive contact layer being a buried web provided on said side wall.

A trench capacitor configuration, comprising:

• a substrate formed with a trench;
• said trench having an upper region and a lower region;
• an insulating collar formed in said upper region;
• a buried well disposed in said substrate, said lower region at least partly extending through said buried well;
• a buried plate formed around said lower region and serving as an outer capacitor electrode;
• a dielectric layer lining said lower region and said insulating collar, said dielectric layer serving as a capacitor dielectric;
• a conductive trench filling disposed in said trench;
• a conductive contact layer of tungsten nitride disposed, between said substrate and said conductive trench filling, in said trench above said insulating collar;
• a conductive buried bridge disposed, above said conductive trench filling, in said trench;
• and
• said conductive buried bridge providing an electrical contact between said conductive trench filling and said conductive contact layer.