SEMICONDUCTOR MEMORY DEVICE AND METHOD FOR FORMING THEREOF

摘要

A semiconductor memory device and a method for forming the same are provided to improve reliability and operation characteristic of the semiconductor memory device and to simplify a fabrication process thereof by forming contact plugs without damage of a lower layer and having different heights simultaneously. A semiconductor substrate(110) includes a first region(A) having a cell region and a second region(B) having a peripheral region. First transistors are located on the semiconductor substrate. A first protective layer(170) covers the first transistors. A first dielectric(180) is located on the first protective layer. A semiconductor pattern(210) is located on the first dielectric of the first region. Second transistors are located on the semiconductor pattern. A second protective layer(270) covers the second transistors. A second dielectric(280) is located on the second protective layer and the first dielectric of the second region. The semiconductor pattern is not arranged on the second region. The second protective layer is not arranged on the second region.