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.
|出版ステータス||Published - 2005 6 17|
|イベント||14th Biennial Conference on Insulating Films on Semiconductors - |
継続期間: 2005 6 22 → 2005 6 24
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