Facing-targets-type sputtering apparatus and method
View Patent ↗Disclosed is a facing-targets-type sputtering apparatus and method capable of forming a metal film under the conditions of low gas pressure and low discharge voltage. An opening is formed in each of two facing side faces of a vacuum chamber vessel or in each of two facing side faces of a box-type discharge unit attached to an opening portion of a vacuum chamber vessel. The two openings are covered by a pair of cooling blocks. Each cooling block holds a target facing a discharge space. Magnetic field generation means is disposed so as to surround each target and operative to generate a magnetic field that surrounds a discharge space provided between the paired targets. Electron reflection means is disposed above the exposed surface of each target along the periphery of the target. A DC power and a high-frequency power are applied between the vacuum chamber vessel and the targets.
1. A facing-targets sputtering method for producing a film on a substrate which comprises:
(a) generating a magnetic field extending between two targets from one target to the other, the targets being disposed a predetermined distance away from each other, in such a manner as to surround a discharge space provided between the two targets, to thereby confine plasma within the discharge space by means of the magnetic field; and
(b) performing sputtering under vacuum to form a film on a substrate disposed at a position beside the discharge space, wherein
electrons are caused to be reflected into the discharge space by use of electron reflection means disposed around the corresponding targets, and
power generated through superposition of high frequency power to direct current power is applied to the targets to effects the sputtering;
wherein a film is formed at a gas pressure of 0.5 Pa or lower.
2. A facing-targets sputtering apparatus for producing a film on a substrate comprising:
a box unit having a discharge space provided therein and having at least three openings formed in corresponding three side faces thereof including two facing side faces;
a pair of target units disposed so as to cover the corresponding two facing openings, each unit having a target on the discharge space side;
a substrate holder for holding a substrate in such a manner so as to cause the substrate to face the opening remained open and be perpendicular to the pair of target units; and
a power supply unit for supplying direct-current power and high-frequency power to the paired targets, wherein said paired target units each comprises:
a cooling block for holding the corresponding target on a surface thereof;
magnetic field generation means for generating a magnetic field in such a manner as to surround the discharge space; and
electron reflection means for reflecting an electron to the discharge space disposed on the magnetic field generation means in such a manner as to surround the corresponding target.
3. A facing-targets sputtering apparatus according to claim 2 , wherein the discharge space is evacuated at a gas pressure of 0.5 Pa or lower when a film is formed.
4. A facing-targets sputtering method for producing a film on a substrate which comprises:
(a) generating a magnetic field extending between two targets from one target to the other, the targets being disposed a predetermined distance away from each other, in such a manner as to surround a discharge space provided between the two targets, to thereby confine plasma within the discharge space by means of the magnetic field; and
(b) performing sputtering under vacuum to form a film on a substrate disposed at a position beside the discharge space, wherein
electrons are caused to be reflected into the discharge space by use of electron reflection means disposed around the corresponding targets, and
power generated through superposition of high frequency power to direct current power is applied to the targets to effect the sputtering;
wherein the side faces of the discharge are closed except for a side face which faces the substrate.
5. A facing-targets sputtering method according to claim 4 , wherein in addition to the magnetic field extending between the targets from one target to the other, a circular arc magnetic field is generated at a peripheral edge portion of each target.
6. A facing-targets sputtering method according to claim 4 , wherein a film is formed at a gas pressure of 0.5 Pa or lower.
7. A facing-targets sputtering method according to claim 4 , wherein a side face opposite to the side face facing the substrate is closed by a target unit.
8. A facing-targets sputtering method according to claim 4 , wherein the electron reflection means and the targets are made of the same material.
9. A facing-targets sputtering method according to claim 4 , wherein the targets are of Cu, a Cu alloy, Al, or an Al alloy.
10. A facing-targets sputtering method according to claim 9 , wherein the film is a conducting film.
11. A facing-targets sputtering method according to claim 10 , wherein the film is a metal film.
12. A facing-targets sputtering method according to claim 10 , wherein the film is formed at a gas pressure of 0.05 Pa or lower.
13. A facing-targets sputtering method according to claim 4 , wherein a sputtering unit comprising the facing targets is a box sputtering unit configured to close side faces of the discharge space except for a side face facing the substrate; and the film is formed at a gas pressure of 0.01 Pa or lower.
14. A facing-targets sputtering method according to claim 13 , wherein a side face opposite to the side face facing the substrate is closed by a target unit.
15. A facing-targets sputtering method according to claim 14 , wherein the film is of Cu, a Cu alloy, Al, or an Al alloy.
16. A facing-targets sputtering method according to claim 13 , wherein the film is a metal film.
17. A facing-targets sputtering method according to claim 16 , wherein the film is a wiring film of a semiconductor device.