| abstract |
PROBLEM TO BE SOLVED: To improve electric contact between a metal plug and a semiconductor region, usually, a refractory metal layer is deposited on a contact area, Next, it is necessary to anneal the work piece so that the atoms of the semiconductor material and the refractory metal diffuse into each other, and to form a compound such as a refractory metal silicide when the semiconductor is silicon. According to one embodiment of the present invention, a refractory metal is coated on a substrate (1). This is a method of depositing in the contact area 17 of the semiconductor region 12 on the zero. The contact area 17 is first exposed by exposing the substrate 10 to a plasma containing a fluorine-containing species to clean the contact area 17, and then the substrate 10 is preferably exposed to a plasma containing hydrogen-containing gas to capture fluorine generated by the plasma decomposition. 2. Cleaning by a two-step process that is exposed to the atmosphere. Next, a refractory metal is deposited on the contact area 17. The two-step cleaning process can reduce the electrical resistance between the refractory metal and the semiconductor region 12. Further, as the substrate 10 is annealed to diffuse the semiconductor material and the refractory metal atoms into each other, the two-step cleaning process may reduce the annealing temperature required to achieve the desired low electrical resistance. |