| 摘要 |
The present invention discloses a multi-diameter electrical conductor for use as an embedded plug in a microelectronic device. The multi-diameter electrical conductor consists of a body portion which has a first diameter, and at least one neck portion in contact with the body portion that has at least a second diameter smaller than the first diameter. In a preferred embodiment, the multi-diameter conductor is a dual-diameter conductor providing electrical communication between an electrode and an active circuit element in a semiconductor structure and comprising a lower body portion and an upper neck portion. The conductive materials used in forming the body portion and the neck portion of the contact plug can be selected from doped polysilicon, refractory metals, metal silicides, low resistivity metals, noble metals and their alloys, adhesion layers, metallic diffusion barrier layers, and oxide and nitride diffusion barrier materials. In a preferred embodiment, the body portion is formed of a first conductive material while the neck portion is formed of a second conductive material. In an alternate embodiment, the body portion and the neck portion are formed of the same conductive material. In another alternate embodiment, the contact plug further includes an additional layer of a conductive material situated between the body portion and the neck portion formed of a material different than that used in forming the body portion and the neck portion. The additional layer of conductive material has a diameter not less than the diameter of the neck portion and not more than the diameter of the body portion.
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