Method of forming metal layers formed as a composite of sub-layers using Ti texture control layer

摘要

In an integrated circuit, an opening (e.g., via or window) is filled with an Al-based plug which has essentially a <111> orientation and comprises at most three grains. These characteristics are achieved by first depositing a texture control Ti layer having substantially a (002) basal plane orientation followed by at least three Al-based sublayers. The grain sizes and deposition conditions are controlled in such a way that during deposition of the third sublayer, the microstructure of the plug adjusts itself to produce a single grain (or at most three).