Manufacturing method for high capacitance capacitor structure

A manufacturing method of high capacitance capacitor structure, comprising the steps of:

• providing a substrate (15) having a first oxide layer (17) formed on a top surface thereof;
• forming a first suspension layer (11) on the first oxide layer;
• forming a first shallow trench (13) through the first suspension layer into the first oxide layer above the substrate;
• forming a second oxide layer on the first suspension layer (11) and filling the first shallow trench;
• forming a second suspension layer (12) on the second oxide layer;
• forming a second shallow trench (14) through the second suspension layer (12) into the second oxide layer above the first suspension layer (11);
• forming at least one deep trench (16) on the bottom surface of the second shallow trench (14) through the first oxide layer (17) and the second oxide layer, the cross-section of the deep trench (16) being smaller than that of the second shallow trench (14);
• forming a electrode layer (18) on the inner surface of the deep trench;
• and
• removing the first oxide layer and the second oxide layer through the trench openings in the first and the second suspension layers.