Work function (φ m) of metal transistor gates was controlled by using Al-Ni and Ni-Ta alloys made through an interdiffusion process, in which stacks of different metals were annealed. In addition to conventional capacitance-voltage measurements for φ m evaluation, φ m uniformity was also measured microscopically. The average φ m of the Al-Ni alloy was successfully changed compared to that of pure Al by interdiffusion at 500 °C. The φ m nonuniformity of Al-Ni, however, was problematic. Though Ni-Ta alloys required interdiffusion at a higher temperature of 700 °C, the Ni-Ta alloys had better φ m uniformity. Thus, the Ni-Ta alloy is a more suitable candidate for use in metal gates of high-integrity transistors.
|Number of pages||4|
|Publication status||Published - 2005 Jun 17|
|Event||14th Biennial Conference on Insulating Films on Semiconductors - |
Duration: 2005 Jun 22 → 2005 Jun 24
- Metal gate
- Work function