Method and apparatus for magnetron discharge type sputtering

Claim 1

A magnetron discharge type cathode for a sputtering apparatus comprising: a flat circular target; a magnetic field application unit disposed on the back side of the flat circular target, and rotating means for rotating the magnetic field provided on the front surface of said flat circular target by said magnetic field application unit; wherein said magnetic field application unit has magnetic poles and sets up a magnetic field, the arrangement of the magnetic poles and the strength of the magnetic field being such that, when the magnetic field is rotated, there are n plasma groups on the j-th circle of a radius r j from the center of rotation of the rotating magnetic field, and m plasma groups on the j+1 th circle of a radius r j+1 from the center of rotation of the rotating magnetic field, and wherein said circular target erodes at an erosion rate D r .sbsb.j (Å/min) for parts of said target on the j th circle of radius r j and said target erodes at an erosion rate D r .sbsb.j+1 (Å/ min) for parts of said flat circular target on the j+1 th circle of radius r j+1 in accordance with the equations, respectively: ##EQU22## where i, j, and k are positive integers, respectively, where R r .sbsb.j.spsb.i and R r .sbsb.j+1.spsb.k (Å/min) are the erosion rates under a stationary magnetic field provided by the i-th plasma group that is found on the j-th circle of the radius r j , and that provided by the k th plasma group that is found on the j+1 th circle of the radius r j+1 , respectively, and which erosion rates increase according to the increase of magnetic field strength, where θ r .sbsb.j.spsb.i and θ r .sbsb.j+1.spsb.k are circumferential angles provided by a ratio of an arc length L r .sbsb.j.spsb.i or the i-th plasma to distance r j from the center of rotation and by a ratio of an arc length L r .sbsb.j+1.spsb.k of the k th plasma group to a distance r j+1 from the center of rotation, and where there is a relation D r .sbsb.j >D r .sbsb.j+1 for the radius r j of the j-th circle and the radius r j+1 of the j+1-th circle (r j >r j+1 ).

Claim 14

A method for sputtering a flat circular target using plasma generated by a magnetron discharge type cathode, comprising; applying a magnetic field to said flat circular target by magnetic poles disposed in back of said flat circular target, rotating the magnetic field provided on the front surface of said flat circular target by said magnetic field application, and arranging said magnetic poles and the strength of said magnetic field such that, when said magnetic field is rotated, there are n plasma groups on a j-th circle of a radius r j from the center of rotation of the rotating magnetic field and m plasma groups on the j+1 th circle of a radius r j+1 from the center of rotation of the rotating magnetic field, and an erosion rate D r .sbsb.j (Å/min) of various parts of said flat circular target on the j-th circle of radius r j and that said target erodes at an erosion rate D r .sbsb.j+1 (Å/min) for parts of said flat circular target on the j+1 th circle of radius r j+1 in accordance with the equations, respectively: ##EQU31## where i, j, and k are each positive integers, where R r .sbsb.j.spsb.i and R r .sbsb.j+1.spsb.k (Å/min) are the erosion rates under a stationary magnetic field provided by the i-th plasma group that is found on the j-th circle of the radius r j , and that provided by the k th plasma group that is found on the j+1 th circle of the radius r j+1 , respectively, and which erosion rates increase according to the increase of magnetic field strength, and where θ r .sbsb.j.spsb.i and θ r .sbsb.j+1.spsb.k are the ratio of the arc length L r .sbsb.j.spsb.i of the i-th plasma to distance r j from the center of rotation, and the ratio of the arc length L r .sbsb.j+1.spsb.k of the i-th plasma to a distance r j+1 from the center of rotation, respectively, and wherein D r .sbsb.j >D r .sbsb.j+1 where the radius r j of the j-th circle is larger than the radius r j+1 of the j+1-th circle (r j >r j+1 ).

Claim 15

A method for sputtering a flat circular target using plasma generated by a magnetron discharge type cathode, comprising; applying a magnetic field to said flat circular target by magnetic poles disposed in back of said flat circular target, rotating the magnetic field provided on the front surface of said flat circular target by said magnetic field application, and arranging said magnetic poles and the strength of said magnetic field such that, when said magnetic field is rotated, there are n plasma groups on a j-th circle of a radius r j from the center of rotation of the rotating magnetic field and m plasma groups on the j+1 th circle of a radius r j+1 from the center of rotation of the rotating magnetic field, and an erosion rate D r .sbsb.j (Å/min) of various parts of said flat circular target on the j-th circle of radius r j and that said target erodes at an erosion rate D r .sbsb.j+1 (Å/min) for parts of said flat circular target on the j+1 th circle of radius r j+1 in accordance with the equations, respectively: ##EQU31## where i, j, and k are each positive integers, where R r .sbsb.j.spsb.i and R r .sbsb.j+1.spsb.k (Å/min) are the erosion rates under a stationary magnetic field provided by the i-th plasma group that is found on the j-th circle of the radius r j , and that provided by the k th plasma group that is found on the j+1 th circle of the radius r j+1 , respectively, and which erosion rates increase according to the increase of magnetic field strength, and where θ r .sbsb.j.spsb.i and θ r .sbsb.j+1.spsb.k are the ratio of the arc length L r .sbsb.j.spsb.i of the i-th plasma to distance r j from the center of rotation, and the ratio of the arc length L r .sbsb.j+1.spsb.k of the i-th plasma to a distance r j+1 from the center of rotation, respectively, and wherein D r .sbsb.j >D r .sbsb.j+1 where the radius r j of the j-th circle is larger than the radius r j+1 of the j+1-th circle (r j >r j+1 ).