Paper PS-ThP44
Study on the Plasma Damage on the Interface between the Titanium Nitride and Hafnium Oxide during Etching Carbon Mask on the Titanium Nitride

Thursday, November 1, 2012, 6:00 pm, Room Central Hall

We investigated the etch damage on the interface between the titanium nitride(TiN) and hafnium oxide(HfO2) during etching the carbon layer on the TiN. HfO2 is widely used as a high-k gate dielectric material to reduce the gate leakage current and improve the reliability in the semiconductor device. TiN and amorphous carbon layer(ACL) are deposited on the HfO2 as a gate electrode and mask material, respectably. We fabricated complimentary metal oxide semiconductor (CMOS) devices with patterning ACL on the TiN by dry etching and removing the TiN layer by wet chemical. We realized that an interlayer between the TiN and HfO2 layer was generated due to the plasma damage during the ACL etching and the interlayer was not removed clearly by the wet chemical, which resulted in device degradations. We studied the properties of the interlayer with changing the ACL etching recipe to find the key factor of generating the interlayer. The properties changed significantly with the ion energy and the gas composition of the ACL etch recipe.