Barrier Property of W-Silicide and Ta-Nitride for Cu Metallization

• Main Authors: Lin, Yueh-Chiou, 林月秋
• Other Authors: Chen Mao-Chieh
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/41050962115026989006

碩士 === 國立交通大學 === 電子工程學系 === 85 === This thesis studies the diffusion barrier properties of W- silicide and Ta-nitride with respect to Cu metallization. The W-silicide films were depositedby low pressure chemical vapor deposition using the SiH4 reduction of WF6 process. The Ta- nitride films were deposited using reactive sputtering in Ar/ N2 mixing ambient. In the electrical aspect, leakage current measurement on the Cu/barrier/p+n junction diodes and capacitance-voltage measurement on the Cu/barrier/SiO2/Si MOS capacitors were used to characterize the capacity of barrier in the metallization system. Degradation mechanism of the barrier films was investigated using the measurement and analysis techniques of sheet resistance, XRD, SEM, AFM, SIMS, and AES. For the Cu/WSix/p+n junction diodes with a WSix barrier of 50nm, the thermal stability of the diodes was found to reach 500℃; an in-situ N2 plasma treatment on the surface of WSix raised the stability temperature to 600℃. For the Cu/TaNx/p+n junction diodes, the thermal stability of the diodes was found to reach 700℃ for 25nm of TaNx, 600℃ for 10nm of TaNx, and 500℃ for 5nm of TaNx. For the Cu/TaNx/SiO2/Si MOScapacitors, a barrier film of 10nm thickness is able to maintain the devices integrity up to 700℃.