Semiconductor memory device with trench capacitor and method for the production thereof

Method for producing a semiconductor memory configuration in a semiconductor substrate having memory cells each including one trench capacitor and one MOS selection transistor, which comprises:

• forming a trench with an inner trench wall and an upper edge in a semiconductor substrate for receiving a capacitor;
• producing a first insulating layer on the inner trench wall;
• depositing a conducting or insulating layer and anisotropically etching back;
• forming an opening in the first insulating layer at a location on the upper edge of the trench for producing a contact with the substrate;
• depositing a first conducting layer bonding the substrate through the opening and forming a first electrode of the capacitor by anisotropically etching back;
• depositing a second insulating layer as a dielectric of the capacitor;
• depositing a second conducting layer filling the trench and texturing the second conducting layer to form a second electrode;
• producing a transistor in the vicinity of the trench with a conducting region of the transistor in electrical contact with the first electrode through the opening in the first insulating layer;
• and
• producing word lines and bit lines.

Method for producing a semiconductor memory configuration having memory cells each including one trench capacitor and one MOS selection transistor, in a semiconductor substrate having a surface, which comprises:

• forming a trench with an inner trench wall in a semiconductor substrate down to the depth of a trench contact to be subsequently produced;
• applying a protective layer for the trench contact;
• removing the protective layer from surfaces parallel to the substrate surface and from part of the inner trench wall;
• deepening the trench down to the total depth of a capacitor to be subsequently produced;
• applying a first insulating layer to the inner trench wall;
• removing the remaining protective layer at the upper edge of the trench to produce the trench contact;
• depositing and anisotropically etching back a first conducting layer forming a first electrode of the capacitor and producing the trench contact;
• depositing a second insulating layer as a dielectric of the capacitor;
• depositing a second conducting layer filling the trench and texturing the second conducting layer to forms a second electrode;
• producing a transistor in the vicinity of the trench with a conducting region of the transistor in electrical contact with the first electrode through an opening formed in the first insulating layer;
• and
• producing word lines and bit lines.