Storage device and forming method therefor

A method for forming a memory device, comprising:

• providing a semiconductor substrate, forming a plurality of discrete active regions extending along a first direction in the semiconductor substrate, the plurality of active regions being isolated by an isolation layer, forming two parallel word lines extending along a second direction in each active region and a corresponding isolation layer, the two parallel word lines dividing each active region into a drain region located between the two parallel word lines and source regions located outside of the word lines respectively, and a first acute angle being provided between the first direction and the second direction;
• forming a plurality of parallel mask patterns extending along a third direction on the semiconductor substrate by adopting a self-alignment multi-pattern process, providing an opening between the adjacent mask patterns, the opening exposing surfaces of a plurality of the drain regions and corresponding isolation layers in the third direction;
• using the plurality of parallel mask patterns as masks, etching the drain region and the corresponding isolation layer along the opening to form a plurality of parallelly distributed trenches in the drain region and the corresponding isolation layer;
• filling the trench with a conductive layer to form a strip-shaped bitline contact structure;
• breaking the strip-shaped bitline contact structure to form a plurality of bitline contact blocks connected with corresponding drain regions;
• and
• forming a bitline connecting the plurality of bitline contact blocks along a direction perpendicular to the second direction.