New technologies in isolation and capacitor process for sub 0.1μm DRAM

New technologies for sub 0.1 μm DRAM devices are reviewed and discussed in views of shallow trench isolation and capacitor process. In order to enhance the gap filling and reduce the accumulated mechanical stress in STI, Polysilazane-SOG pillar is introduced at the trench bottom. Additionally, poly-Si filling process is also developed to minimize channel edge effect. HfO₂ deposited by atomic layer deposition is employed to lower the Toxeq. down to about 25Å. Toxeq. can be reduced further by introduction of TiN metal electrode. TiN electrode capacitor of Toxeq. 15Å shows the stable leakage current. Ru electrode help Toxeq. scale down to 10Å. It is concluded that sub 0.1 μm devices can be manufacturable through the introduction of new technologies and materials.