Process for manufacturing a semiconductor memory device

A process of manufacturing a semiconductor memory device comprising the steps of:

• selectively implanting, into a main surface of a semiconductor substrate of a first type of conductivity, a second type of conductivity forming impurity so as to form impurity implanted regions of said first type of conductivity which are higher in resistivity than said semiconductor substrate;
• epitaxially growing surface regions on said semiconductor substrate including said impurity implanted regions, said surface regions being similar in resistivity to said impurity implanted regions;
• forming a bit line region of said second type conductivity in said surface regions except for a portion of said surface regions which are disposed on said impurity implanted regions, said bit line region reaching said semiconductor substrate from the surface of said surface regions;
• and forming a gate electrode of a transfer gate transistor above said surface regions and also above said impurity implanted regions through an electrically insulating material and forming through said electrically insulating material an electrode of a capacitor above a portion of said surface regions which are located opposite to said bit line region with respect to said portion of said surface regions disposed on said impurity implanted regions.