Sputtering system using cylindrical rotating magnetron electrically powered using alternating current
First Claim
1. A sputtering system for forming a dielectric layer on a substrate comprising:
- an alternating current power supply having a first and a second pole that alternate in polarity;
a chamber;
a rotatable magnetron in said chamber, said rotatable magnetron including a cylindrical tubular target of electrically conductive material responsive to the power signal at the first pole of the alternating current power supply and a magnet assembly adapted to direct the plasma to form an erosion zone on the cylindrical tubular target, the erosion zone being the area sputtered when the negative portion of the power supply is supplied to the cylindrical tubular target, wherein the cylindrical tubular target is adapted to rotate such that the erosion zone is located at different parts of the cylindrical target as the cylindrical target rotates and so that the sputtering of the target removes some dielectric material deposited onto the target to form a cleaned portion of the target and wherein the removal of the dielectric from the cleaned portion of the target in portions away from the erosion zone reduces the impedance of the target as seen by the electrodes in the plasma when the positive portion of the power supply is supplied to the cylindrical tubular target and thus may prevent arcing, andan electrically conductive member in the chamber responsive to the power signal at the second pole of the alternating current supply.
7 Assignments
0 Petitions
Accused Products
Abstract
A sputtering system using an AC power supply in the range of 10 kHz to 100 kHz uses two rotatable cylindrical magnetrons. The rotatable cylindrical magnetrons, when used for depositing a dielectric layer onto a substrate, clean off dielectric material that is deposited onto the target. This prevents a dielectric layer on the target from acting like a capacitor and may help avoid arcing. Additionally, an impedance-limiting capacitor can be placed in series in the electrical path between the targets through the transformer so as to reduce arcing. This impedance-limiting capacitor has a value much larger than the capacitors used to couple the power supply to a target in radio frequency sputtering systems.
341 Citations
24 Claims
-
1. A sputtering system for forming a dielectric layer on a substrate comprising:
-
an alternating current power supply having a first and a second pole that alternate in polarity; a chamber; a rotatable magnetron in said chamber, said rotatable magnetron including a cylindrical tubular target of electrically conductive material responsive to the power signal at the first pole of the alternating current power supply and a magnet assembly adapted to direct the plasma to form an erosion zone on the cylindrical tubular target, the erosion zone being the area sputtered when the negative portion of the power supply is supplied to the cylindrical tubular target, wherein the cylindrical tubular target is adapted to rotate such that the erosion zone is located at different parts of the cylindrical target as the cylindrical target rotates and so that the sputtering of the target removes some dielectric material deposited onto the target to form a cleaned portion of the target and wherein the removal of the dielectric from the cleaned portion of the target in portions away from the erosion zone reduces the impedance of the target as seen by the electrodes in the plasma when the positive portion of the power supply is supplied to the cylindrical tubular target and thus may prevent arcing, and an electrically conductive member in the chamber responsive to the power signal at the second pole of the alternating current supply. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A sputtering system for forming a dielectric layer on a substrate comprising:
-
an alternating current power supply having a first and a second pole and adapted to produce a power signal with a frequency of less than a megahertz; a chamber; a transformer having two output terminals and two input terminals, the two input terminals connected between the first and second pole; a cylindrical tubular target of an electrically conductive material with associated magnet assembly located in said chamber electrically connected by a first electrical path to the first output terminal of the transformer; an electrically conductive member in the chamber electrically connected by a second electrical path to the second output terminal of the transformer; and an impedance-limiting capacitor connected in series in the electrical path between the target and the electrically conductive member through the transformer, the capacitance of the impedance-limiting capacitor being sufficiently large that the impedance-limiting capacitor prevents arcing in the system. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 22)
-
-
20. A method for depositing a dielectric layer on a substrate by reactive sputtering comprising the steps of:
-
providing a cylindrical target of a conductive material in a chamber; applying an alternating current signal to the cylindrical target to produce a plasma, said signal having positive and negative portions; producing a magnetic field to produce an erosion zone about the cylindrical target such that ions strike the erosion zone when a negative portion of the signal is applied to the cylindrical target; providing in the chamber a gas which reacts with the target material to form a dielectric; depositing a dielectric layer on the substrate; cleaning portions of the target by rotating the cylindrical target so that portions of the cylindrical target away from the erosion zone defined by the magnetic field have deposited material removed by the bombarding ions of the erosion zone; and attracting electrons in the plasma to the cleaned portions away from the erosion zone when the positive portion of the signal is applied to the target. - View Dependent Claims (21, 23, 24)
-
Specification