CONTACT FORMATION METHOD OF SEMICONDUCTOR MEMORY DEVICES

摘要

PURPOSE: A method for forming a contact of semiconductor memory is provided to simplify manufacturing process and reduce manufacturing cost by skipping a DC(direct contact) process of cell region or a DC process of core region. CONSTITUTION: The method comprises the steps of forming a transistor having a gate (104), a source and drain regions on a substrate (100) divided by cell and core regions; forming an interlayer insulator (106) on the resultant structure; forming a DC pad (110a) and a BC(buried contact) pad (110b) having a step compared to the interlayer insulator (106) and formed between the gates (104); forming an insulating substance (112) having bad step coverage such as PE-TEOS(plasma enhanced tetraethylorthosilicate); etching the insulating substance (112) to expose the DC and BC pads (110a, 110b); forming a first conductive layer (114) on the resultant structure; forming a second conductive layer (116) on the first conductive layer (114); and forming a bit line by etching the second and first conductive layer (116, 114) and simultaneously isolating between the bit line and the first conductive layer by over-etching the first conductive layer formed on the DC pad (110a).