High aspect ratio low resistivity lines/vias by surface diffusion

Claim 1

A method of filling at least one of high aspect ratio vias and lines, said high aspect ratio being greater than or equal to four, on a substrate having an upper surface and for preventing voids being formed in said one of high aspect ratio vias and lines, said method comprising the step of: filling said one of high aspect ratio vias and lines by surface diffusion at room temperature and at a pressure of less than 1 Torr with a sputtered material, step coverage of said material and sputtering parameters satisfying a predetermined relationship comprising: SC=K·M.sub.P.sup.-a ·M.sub.W.sup.-a ·P.sup.-b ·A.sub.R.sup.-c ·θ.sup.-d ·T.sup.e where SC is the step coverage of the material; M P is the melting point of the material; M W is the atomic weight of the material; A R is the aspect ratio of said vias and lines; P is operating pressure (mT); T is substrate temperature (° C.); θ is ARCTAN (D1-D2/2H); K is a material dependent constant; a is 0.2; b is in a range 0.25-0.51 c is in a range 0.21-0.27 d less than or equal to 0.1; e is in a range 0.6-0.7; K is in a range 3-5; D1 comprises a diameter of a sputtering target of the material; D2 comprises a diameter of substrate; and H is a distance between said sputtering target and said substrate, said upper surface having regions containing a group consisting of at least one of exposed aluminum, aluminum-copper and copper alloys and reacting said at least one of aluminum, aluminum-copper and copper alloys with a gas containing germanium to form a germanium alloy on said upper surface.

Claim 2

A method of filling at least one of high aspect ratio vias and lines, said high aspect ratio being greater than or equal to four, on a substrate having an upper surface and for preventing voids being formed in said one of high aspect ratio vias and lines, said method comprising the step of: filling said one of high aspect ratio vias and lines by surface diffusion at room temperature and at a pressure of less than 1 Torr with a sputtered material, step coverage of said material and sputtering parameters satisfying a predetermined relationship comprising: SC=K·M.sub.P.sup.-a ·M.sub.W.sup.-a ·P.sup.-b ·A.sub.R.sup.-c ·θ.sup.-d ·T.sup.e where SC is the step coverage of the material; M P is the melting point of the material; M W is the atomic weight of the material; A R is the aspect ratio of said vias and lines; P is operating pressure (mT); T is substrate temperature (° C.); θ is ARCTAN (D1-D2/2H); K is a material dependent constant; a is 0.2; b is in a range 0.25-0.51 c is in a range 0.21-0.27 d less than or equal to 0.1; e is in a range 0.6-0.7; K is in a range 3-5; D1 comprises a diameter of a sputtering target of the material; D2 comprises a diameter of substrate; and H is a distance between said sputtering target and said substrate, said upper surface having regions containing a group consisting of at least one of exposed aluminum, aluminum-copper and copper alloys and reacting said at least one of aluminum, aluminum-copper and copper alloys with a gas containing germanium to form a germanium alloy on said upper surface.