Magnetron sputter device having planar and concave targets

Claim 2

A vacuum sputtering device for causing material from a target means to be sputtered onto a workpiece, the target means including a first target initially having a planar material emitting surface and a second target initially having a concave emitting surface, the device comprising means for supplying an ionizable gas to a space adapted to be evacuated, the space being between the target and workpiece, means for establishing an ionizing electric field for the gas in the space, means for establishing a confining magnetic field for the gas ionized by the electric field in the vicinity of the emitting surfaces of the first and second targets, and means for mounting the targets so that emitted material is sputtered from the concave emitting surface outside of the first target at an angle displaced from the planar emitting surface.

Claim 3

The device of claim 1 wherein the electric field establishing means and the magnetic field confining means include means for establishing separate first and second discharges in the ionized gas immediately above the emitting surfaces of the first and second targets, said separate discharge establishing means including: means for establishing separate first and second ionizing electric fields for the gas above the first and second targets, respectively, and means for establishing different confining magnetic fields for the gas ionized by the electric fields in the vicinity of the emitting surfaces of the first and second targets, said magnetic field confining means including first and second magnetic circuits through the first and second targets, respectively, the first and second magnetic circuits respectively including first and second magnetic field sources and pole pieces for coupling flux from the first and second magnetic field sources to the first and second targets.

Claim 4

The device of claim 2 further including means for adjusting the relative magnitudes of the first and second magnetic field sources.

Claim 5

The device of claim 3 wherein the magnetic field sources are electromagnets responsive to different adjustable current sources.

Claim 6

A vacuum sputtering device for causing material to impinge on a workpiece comprising target means for sputtering the material, the target means including a first target initially having a planar material emitting surface and a second target initially having a concave emitting surface, the first and second targets being arranged so that emitted material is sputtered from the concave emitting surface outside of the first target at an angle displaced from the planar emitting surface, means for supplying an ionizable gas to a space adapted to be evacuated, the space being between the target and article, means for establishing an ionizing electric field for the gas in the space, and means for establishing a confining magnetic field for the gas ionized by the electric field in the vicinity of the emitting surfaces of the first and second targets.

Claim 7

A vacuum sputtering device for causing material to impinge on a workpiece comprising target means for sputtering the material, the target means including a first target initially having a planar material emitting surface and a second target initially having a concave emitting surface, the first and second targets being arranged so that emitted material is sputtered from the concave emitting surface outside of the first target at an angle displaced from the planar emitting surface, means for supplying an ionizable gas to a space adapted to be evacuated, the space being between the target and article, means for establishing an ionizing electric field for the gas in the space, and means for establishing a confining magnetic field for the gas ionized by the electric field in the vicinity of the emitting surfaces of the first and second targets.

Claim 8

The device of claim 5 wherein the planar emitting surface has an annular configuration with inner and outer radii of R 1 and R 2 , respectively, the concave emitting surface being symmetrical about a longitudinal axis of the annular planar emitting surface and having inner and outer radii of R 3 and R 4 , respectively wherein R 1 <R 2 <R 3 <R 4 .

Claim 9

The device of claim 6 wherein the concave surface is defined by a side wall of a frustum of a cone.

Claim 10

The device of claim 7 wherein the concave surface is inclined at approximately 45° relative to the planar emitting surface.

Claim 11

The device of claim 7 wherein the electric field establishing means and the magnetic field confining means includes means for establishing separate first and second discharges in the ionized gas immediately above the emitting surfaces of the first and second targets, said separate discharge establishing means including: means for establishing separate first and second ionizing electric fields for the gas above the first and second targets, respectively, and means for establishing different confining magnetic fields for the gas ionized by the electric fields in the vicinity of the emitting surfaces of the first and second targets, said magnetic field confining means including first and second magnetic circuits through the first and second targets, respectively, the first and second magnetic circuits respectively including first and second magnetic field sources and pole pieces for coupling flux from the first and second magnetic field sources to the first and second targets.

Claim 12

The device of claim 9 wherein the first magnetic circuit includes a first pole piece extending axially along the axis for coupling magnetic flux to radius R 1 of the first target, the second magnetic circuit including a second annular pole piece concentric with the axis for coupling magnetic flux to radius R 4 of the second target, the first magnetic circuit including first pole piece means for coupling magnetic flux to radius R l of the first target, the second magnetic circuit including second pole piece means for coupling magnetic flux to radius R 3 of the second target.

Claim 13

The device of claim 6 wherein the electric field establishing means and the magnetic field confining means include means for establishing separate first and second discharges in the ionized gas immediately above the emitting surfaces of the first and second targets, said separate discharge establishing means including: means for establishing separate first and second ionizing electric fields for the gas above the first and second targets, respectively, and means for establishing different confining magnetic fields for the gas ionized by the electric fields in the vicinity of the emitting surfaces of the first and second targets, said magnetic field confining means including first and second magnetic circuits through the first and second targets, respectively, the first and second magnetic circuits respectively including first and second magnetic field sources and pole pieces - for coupling flux from the first and second magnetic field sources to the first and second targets.

Claim 14

The device of claim 11 wherein the first magnetic circuit includes a first pole piece extending axially along the axis for coupling magnetic flux to radius R I of the first target, the second magnetic circuit including a second annular pole piece concentric with the axis for coupling magnetic flux to radius R 4 of the second target, the first magnetic circuit including first pole piece means for coupling magnetic flux to radius R of the first target, the second magnetic circuit including second pole piece means for coupling magnetic flux to radius R 3 of the second target.

Claim 15

The device of claim 5 wherein the concave surface includes straight cross sectional edges inclined at a constant angle relative to the planar emitting surface.

Claim 16

The device of claim 13 wherein the constant angle is approximately 45°.

Claim 17

The device of claim 5 wherein the planar emitting surface has a circular perimeter and a transverse axis at right angles to the emitting surface, the concave surface being defined by a side wall of a frustum of a cone having an axis coincident with the transverse axis of the planar emitting surface.

Claim 18

A target assembly for a vacuum sputtering device comprising a first target element initially having a planar emitting surface, a second target element initially having a concave emitting surface, the geometries of the first and second targets being such that, when they are in a vacuum, sputtering material is sputtered from the concave emitting surface outside of the first target at an angle displaced from the planar emitting surface.

Claim 19

A target assembly for a vacuum sputtering device comprising a first target element initially having a planar emitting surface, a second target element initially having a concave emitting surface, the geometries of the first and second targets being such that, when they are in a vacuum, sputtering material is sputtered from the concave emitting surface outside of the first target at an angle displaced from the planar emitting surface.

Claim 20

The target assembly of claim 16 wherein the planar emitting surface has a circular perimeter and an axis transverse to the emitting surface, the concave surface being defined by a side wall of a frustum of a cone having an axis coincident with the transverse axis of the planar emitting surface.

Claim 21

The target assembly of claim 17 wherein the concave surface is inclined by approximately 45°.

Claim 22

The target assembly of claim 17 wherein the circular perimeter has a radius R 2 , and the concave surface has inner and outer radii of R 3 and R 4 , respectively, where R 2 <R 3 <R 4 .

Claim 23

The target assembly of claim 19 wherein the first target is formed as a ring, the planar emitting surface being an annulus having an inner radius of R 1 , where R 1 <R 2 .