METHOD FOR FORMING SELF-ALIGNED SILICIDE OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method is provided to form a self-aligned silicide film using a BPSG film and a wet etching method. CONSTITUTION: A method is provided to form a self-aligned silicide film(240) by revealing a desired part by a wet etching using a thickness difference after reflowing a BPSG film according to the density of patterns in a silicide forming process. Poly silicon gates(120) are formed on a semiconductor substrate(100) having a memory cell region(a) and a logic region(b). In the memory cell region, the gates are formed densely, but in the logic region the gates are formed sparsely. An insulation spacer(140) is formed on both side walls of the gates in the memory cell region and the logic region. An MTO film(160) and a silicon nitride film(180) are formed in sequence on the semiconductor substrate including the gates in each region, and then a BPSG film is formed on the whole structure. The BPSG film and the silicon nitride film and the MTO films are removed so that a top of the polysilicon gate is removed in the memory cell region and a top of the polysilicon gate and a junction part between the above gates are revealed in the logic region. And finally, the self-aligned silicide film is formed on the revealed gate top and the junction region. The processes are simplified and the reliability of a product is increased by the method.