CN112342511B

CN112342511B - Plane magnetic control sputtering source

Info

Publication number: CN112342511B
Application number: CN202011023783.7A
Authority: CN
Inventors: 王德苗; 顾为民; 顾骏; 冯斌
Original assignee: Hangzhou Bifanke Electronic Technology Co ltd
Current assignee: Hangzhou Bifanke Electronic Technology Co ltd
Priority date: 2020-09-25
Filing date: 2020-09-25
Publication date: 2023-02-28
Anticipated expiration: 2040-09-25
Also published as: CN112342511A

Abstract

The invention discloses a plane magnetron sputtering source, which comprises a ship-shaped magnetic guide shoe with a sunken groove on the belly, central magnetic steel, a target back plate, a magnetic guide target pressing ring and the like, wherein a central permanent magnetic steel is arranged in the sunken groove and is communicated with cooling water, and the target back plate is directly fixed on the ship-shaped magnetic guide shoe. Compared with the existing plane magnetron sputtering source, the magnetron sputtering source does not need to be provided with a water-cooling cavity and a shielding case, greatly reduces the weight and the volume, and obviously improves the power efficiency of the target.

Description

Plane magnetic control sputtering source

Technical Field

The invention relates to the field of sputtering plating equipment, in particular to a planar magnetron sputtering source.

Background

The planar magnetron sputtering source is generally composed of a magnetic field source, a target back plate, a planar target plate, a target press ring, a water-cooling cavity, a shield cover and the like. The water-cooling cavity is made of non-magnetic conductive materials such as stainless steel or copper aluminum, a magnetic field source which is composed of a magnetic conductive plate, an inner magnetic steel ring and an outer magnetic steel ring is arranged on the magnetic conductive plate is arranged in the water-cooling cavity, a copper target back plate is hermetically fixed at the top of the water-cooling cavity, a planar sputtering target plate is arranged on the target back plate through a heat-conducting medium, and a shielding cover used for limiting external harmful discharge is arranged outside the water-cooling cavity in an insulating mode. The magnetic field source has inner magnetic steel and outer magnetic steel ring arranged on the magnetic conducting plate in opposite polarity, and the magnetic force lines are led from the magnetic poles in the bottom of the inner magnetic steel to the magnetic poles in the bottom of the outer magnetic steel ring via the magnetic conducting plate and finally flow back to the top of the inner magnetic steel from the gap between the top of the outer magnetic steel and the top of the inner magnetic steel ring, i.e. the target surface, to constitute a magnetic loop; the magnetic field source is arranged in the water-cooling cavity, and cooling water of the water-cooling cavity flows into the water-cooling cavity from the water inlet pipe and flows out from the water outlet pipe. The water-cooling cavity, the target back plate, the sputtering target and the magnetic field source are at the same potential and are connected to the cathode of the sputtering power supply, and the shielding cover is connected to the ground potential of the anode of the sputtering power supply. The magnetic field B and the electric field E on the surface of the target form an E multiplied by B field, electrons continuously collide with working gas molecules (such as argon) under the action of the E multiplied by B field to generate ionization to form a plasma ring, positive ions in the plasma are attracted by a negative electric field of the cathode target to bombard the cathode target, and target surface atoms obtain kinetic energy from incident ions to generate sputtering.

The planar magnetron sputtering source is widely applied because the planar target is easy to manufacture. However, such planar magnetron sputtering sources have several drawbacks:

1. the magnetic field source needs to be immersed in a water-cooling cavity, and the whole sputtering source is large and heavy, which brings difficulty to the installation and use of the planar target.

2. The magnetic field source needs inner magnetic steel and outer magnetic steel ring, and because the number of outer magnetic steel is much more than that of inner magnetic steel, the asymmetry of the structure can leak magnetic field outside the outer magnetic steel ring, so that harmful discharge is generated outside the sputtering source, and in order to inhibit the harmful discharge, a bulky grounded shield cover has to be arranged outside the water-cooling cavity in an insulating way.

3. The non-uniformity of the magnetic steel distribution can cause partial electrons to escape, which restricts the improvement of plasma discharge concentration, thereby restricting the power efficiency of the target.

Disclosure of Invention

The invention aims to provide a plane magnetron sputtering source with light structure and high target power efficiency aiming at the defects of the prior art.

The purpose of the invention is realized by the following technical scheme: a plane magnetron sputtering source comprises a ship-shaped magnetic guide shoe made of magnetic conductive materials, a sinking groove formed in the belly of the ship-shaped magnetic guide shoe and a sealing groove formed in the ship edge, a central magnetic steel arranged in the center of the sinking groove, a copper target back plate fixed on the ship edge of the ship-shaped magnetic guide shoe, a flat plate type sputtering target arranged on the copper target back plate through a heat conducting medium, a target pressing ring made of the magnetic conductive materials and pressing the sputtering target on the copper target back plate through magnetic force, and an interface flange fixed on one side of the ship-shaped magnetic guide shoe and provided with a water inlet pipe and a water outlet pipe, wherein the water inlet pipe and the water outlet pipe are communicated with the sinking groove.

Furthermore, the magnetic field source of the planar magnetron sputtering source is composed of a ship-shaped magnetic guide shoe, central magnetic steel with the same polarity arranged at the center of a ship-shaped magnetic guide shoe sink groove and a magnetic conduction target press ring arranged at the top of the ship-shaped magnetic guide shoe ship edge, and the magnetic line of force of the magnetic field source is guided to the ship edge from the lower magnetic pole of the central magnetic steel through the ship-shaped magnetic guide shoe and then returns to the upper magnetic pole of the central magnetic steel through a gap between the magnetic conduction target press ring and the top of the central magnetic steel.

Furthermore, the ship edge of the ship-shaped magnetic guide shoe is provided with a blind screw hole and a sealing groove, a sealing ring is installed in the sealing groove, and the copper target back plate is fixed on the ship edge of the ship-shaped magnetic guide shoe in a sealing mode through the sealing ring and a screw.

Furthermore, the plane magnetron sputtering source is provided with a water-cooling cavity, the water-cooling cavity is composed of a sunken groove of the ship-shaped magnetic guide shoe and a copper target back plate which is hermetically arranged on a ship edge of the ship-shaped magnetic guide shoe through a sealing ring and a screw, and cooling water in the water-cooling cavity flows into the sunken groove of the ship-shaped magnetic guide shoe from a water inlet pipe of the interface flange and flows out of the interface flange from a water outlet pipe.

Furthermore, the central magnetic steel is an independent permanent magnetic steel, or a permanent magnetic steel row formed by splicing a group of magnetic steels with the same polarity in the same direction, and the central magnetic steel is made of one of neodymium iron boron magnetic steel, samarium cobalt magnetic steel or ferrite magnetic steel.

Furthermore, the boat-shaped magnetic conduction pole shoe is made of ferritic stainless steel, martensitic stainless steel or low-carbon steel or pure iron which is subjected to protection treatment such as electroplating, and the boat-shaped magnetic conduction pole shoe is circular, elliptical, square or rectangular.

Further, the sputtering target is one of a circular, rectangular or square planar target, and the material thereof is one of metal, alloy or ceramic.

Furthermore, the target pressing ring is an annular pressing ring which is made of low carbon steel or magnetic conductive stainless steel and is used for pressing the sputtering target on the copper target back plate by utilizing the magnetic force of a magnetic field source, and a sinking space which is matched with the shape of the sputtering target is formed in the inner circle of the annular pressing ring.

Further, the heat conducting medium is one of heat conducting silicone grease, indium, tin and indium-tin alloy.

Compared with the prior plane magnetron sputtering source, the invention has the advantages that:

1. because the plane magnetron sputtering target only has a group of magnetic steels with the same polarity in the middle, the central magnetic steel and the ship-shaped magnetic conduction shoe directly form a magnetic field source with a balanced magnetic field, and all magnetic lines of force of the magnetic field source are concentrated on the target surface, the concentration of plasma and the power efficiency of the target are greatly improved; the discharge voltage of the prior art planar magnetron sputtering source is as high as 800 volts, and the discharge current is difficult to reach dozens of amperes, while the discharge voltage of the planar target of the invention is only about 300 volts, and the discharge current can easily reach dozens of amperes.

2. The magnetic pressure can not be generated on the ship-shaped magnetic guide shoe with good magnetic conductivity, so that the outside of the magnetic field source can not generate a stray magnetic field, the outside of the sputtering source can not generate harmful discharge, and a shielding cover does not need to be erected outside the plane target.

3. The target back plate is directly sealed and fixed at the top of the ship-shaped magnetic guide shoe through a screw and a sealing ring, and the sink groove of the magnetic guide shoe and the target back plate directly form a water-cooling cavity of the target. Therefore, a water-cooling cavity with large volume can be saved, the volume of the plane target is greatly reduced, the weight is greatly reduced, and the installation and the use are convenient.

4. It is known that in the E × B field of a magnetron sputtering source, only the horizontal magnetic field component parallel to the target surface contributes to sputtering, that is, the larger the horizontal magnetic field component on the target surface is, the higher the sputtering efficiency is, and the wider the horizontal magnetic field distribution is, the wider the sputtering area of the target is, and the higher the target utilization rate is. The sputtering source of the invention directly forms the magnetic field source by the central magnetic steel and the magnetic conduction shoe, the magnetic force lines of the magnetic field source are all concentrated on the target surface, and the magnetic conduction target press ring also plays a role of guiding the horizontal magnetic field, so that the horizontal magnetic field component on the target surface is greatly increased, the horizontal magnetic field distribution is widened, the sputtering area on the target surface is widened, and the utilization rate of the target material is greatly improved.

Drawings

FIG. 1 is a sectional view of a planar magnetron sputtering source according to the present invention. FIG. 2 is a partial cross-sectional view of a rectangular planar magnetron sputtering source of the present invention.

In the figure, 2, the ship-shaped magnetic guide shoe; 2-1, a ship edge of the ship-shaped magnetic guide shoe, and 2-2, a sinking groove of the ship-shaped magnetic guide shoe; 3. a sealing groove; 4. a seal ring; 5. blind screw holes; 6. a central magnetic steel; 7. magnetic lines of force; 8. a copper target backing plate; 9. a heat-conducting medium; 10. a flat plate-type sputtering target; 12. a target compression ring; 13. a water inlet pipe; 14. a water outlet pipe; 15. an interface flange.

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

As shown in fig. 1 and fig. 2, the planar magnetron sputtering source of the present invention mainly includes a boat-shaped magnetic shoe 2, a central magnetic steel 6, a copper target backing plate 8, a planar sputtering target 10, a target pressing ring 12 made of magnetic conductive material, and an interface flange 15.

The ship-shaped magnetic guide shoe 2 is made of magnetic conductive materials, a sunken groove 2-2 of the ship-shaped magnetic guide shoe is formed in the belly of the ship-shaped magnetic guide shoe, a sealing groove 3 and a plurality of blind screw holes 5 are formed in the ship edge 2-1 of the ship-shaped magnetic guide shoe, a central magnetic steel 6 is arranged at the bottom center of the sunken groove 2-2 of the ship-shaped magnetic guide shoe through magnetic force and an adhesive, a copper target back plate 8 is hermetically fixed on the ship edge 2-1 of the ship-shaped magnetic guide shoe through a sealing ring 4 and a plurality of screws, a flat sputtering target 10 made of sputtering materials is arranged on the copper target back plate 8 through a heat conducting medium 9, and a flat sputtering target pressing ring 12 made of magnetic conductive materials and internally provided with sunken gaps matched with the flat sputtering target tightly presses the flat sputtering target 10 on the copper target back plate 8 through magnetic force of a magnetic field source.

The central magnetic steel 6, the ship-shaped magnetic guide shoe 2 and the magnetic target press ring 12 form a magnetic field source. The magnetic line of force 7 of the magnetic field source is guided from the bottom magnetic pole of the central magnetic steel 6 to the ship edge 2-1 of the ship-shaped magnetic guide shoe through the ship-shaped magnetic guide shoe 2, and returns to the top magnetic pole of the central magnetic steel 6 through the gap between the magnetic conductive target press ring 12 and the top magnetic pole of the central magnetic steel 6, namely the target surface, so as to form a magnetic loop of the magnetic field source. The central magnetic steel 6 can be a permanent magnetic steel or a magnetic steel row formed by arranging a plurality of same polarities, and is fixed at the bottom center of the sunken groove 2-2 of the ship-shaped magnetic guide shoe by utilizing magnetic force and adhesive.

The central magnetic steel 6 is one of neodymium iron boron magnetic steel, samarium cobalt magnetic steel and ferrite magnetic steel. The ship-shaped magnetic guide shoe is made of one of commercially available ferritic stainless steel, martensitic stainless steel, pure iron and low-carbon steel, and when the ship-shaped magnetic guide shoe is made of pure iron or low-carbon steel, the surface of the ship-shaped magnetic guide shoe needs to be subjected to anticorrosive treatment such as electroplating. The ship-shaped magnetic guide shoe is one of rectangular, square, round and oval. The target press ring 12 is made of pure iron, mild steel or magnetic-conductive stainless steel, and a sink spacer which is adapted to the shape of the sputtering target 10 is arranged in the target press ring.

A flat plate-shaped sputtering target 10 is arranged on a copper target backing plate 8 by a target press ring 12 through a heat transfer medium 9. The target compression ring has two functions: firstly, the magnetic force of the magnetic field is utilized to suck the sputtering target, and then the flat-plate sputtering target 10 is tightly pressed on the target back plate 8; and secondly, the magnetic flux is guided to extend to the horizontal direction as much as possible.

The flat plate type sputtering target plate is one of a round, square and rectangular plane target plate, and the material of the flat plate type sputtering target plate is one of metal, alloy and ceramic.

The heat conducting medium 9 is one of indium, tin, indium-tin alloy or heat conducting silicone grease.

As shown in fig. 2, a through hole is formed on one side of the boat-shaped magnetic guide shoe 2, and a stainless steel interface flange 15 compatible with the interface of the sputtering system, which is provided with a water inlet pipe 13 and a water outlet pipe 14, is sealed on the through hole on the side surface of the boat-shaped magnetic guide shoe. The interface flange 15 is compatible with the existing plane target and rotating target interfaces, and can be conveniently and interchangeably connected to the existing plane target or rotating target interfaces.

As shown in figures 1 and 2, the water cooling cavity of the plane magnetron sputtering source is composed of a sunken groove 2-2 of a ship-shaped magnetic guide shoe and a copper target back plate 8 which is hermetically arranged on a ship edge 2-1 of the ship-shaped magnetic guide shoe through a sealing ring 3 and a screw, cooling water flows into a space between the sunken groove 2-2 of the ship-shaped magnetic guide shoe and the copper target back plate 8 from a water inlet pipe 13 and flows out from a water outlet pipe 14 to form a water cooling system of the target. The water inlet pipe and the water outlet pipe are different in length, and the purpose of the water inlet pipe and the water outlet pipe is to enable water flow to flow through the whole water cooling cavity as far as possible. The cooling water flowing in the sink groove cools the target back plate in time so as to indirectly conduct away the heat of the sputtering target.

The planar magnetron sputtering source of the present invention may be shaped as a circular, square or rectangular, and the corresponding sputtering target is a flat plate target of circular, square or rectangular shape. Figure 2 shows the structure of a rectangular planar magnetron sputtering source.

Interface flange 15, the magnetic field source, the target back plate, the target press ring and the sputtering target form a sputtering source whole body, are arranged on a target interface of a vacuum system through the interface flange 15, are connected to the negative pole of a sputtering power supply, and the positive pole of the sputtering power supply is grounded. When in vacuum system, up to 10 ^-3 After the vacuum degree above Pa, working gas (such as argon) is dynamically introduced into the vacuum cavity, the sputtering power supply is switched on, an annular E × B field is generated on the target surface of the sputtering source, electrons are subjected to endless Romb motion in the E × B field, the electrons in motion collide with argon molecules, the argon molecules are ionized, a plasma ring similar to the E × B field in shape is generated above the target surface, and positive ions (Ar) in the plasma are generated ⁺ ) The negative electric field of the cathode target attracts and bombards the target surface, and the atoms on the target surface obtain kinetic energy from the incident ions and escape from the target surface to generate sputtering.

Examples

A rectangular planar magnetron sputtering source as shown in FIG. 2 was fabricated by the present invention, in which a boat-shaped magnetic shoe was machined from 400 series Martian stainless steel, and had a length of 580mm, a width of 95mm and a thickness of 32mm, and the size of a sputtering target plate was 568mm, 82mm and 8mm. The central magnetic steel row is formed by splicing 11 neodymium iron boron magnetic steels which are 50mm long, 20mm wide, 25mm high and magnetized in the height direction into a row in the same polarity. The planar magnetron sputtering source is arranged on the interface of the original rotary target and pumped to 5 × 10 ^-3 After Pa vacuum, dynamically filling with 5 x 10 ^-1 And (3) the argon of Pa is connected with a sputtering power supply, the maximum sputtering current reaches more than 30 amperes, the sputtering voltage is only about 310 volts, and the discharge and ignition phenomena do not occur outside the ship-shaped magnetic conduction shoe during operation. The etching area on the sputtering target surface reaches more than 85 percent, the target utilization rate of the sputtering target reaches more than 55 percent after continuous operation for dozens of hours, the target utilization rate of the plane target in the prior art is only about 30 percent, the sputtering voltage of the plane magnetron sputtering source of the target with the same size is as high as 800 volts, and the maximum sputtering current is hardly over 15 amperes. Compared with the prior art, the volume of the sputtering source is greatly reduced, the weight is greatly reduced, the sputtering area of the target is greatly expanded, and the utilization rate of the target material and the power efficiency of the target are obviously improved.

The above-described embodiments are intended to illustrate rather than to limit the invention, and any modifications and variations of the present invention are within the spirit of the invention and the scope of the appended claims.

Claims

1. A plane magnetron sputtering source comprises a magnetic field source, a water-cooling cavity and a sputtering target, and is characterized in that the plane magnetron sputtering source comprises a ship-shaped magnetic guide shoe which is made of magnetic conductive materials, provided with a sink groove at the belly and provided with a sealing groove at the ship edge; a group of central magnetic steels which are arranged at the center of the sinking groove and have the same polarity arrangement; a copper target back plate which is sealed and fixed on the ship edge of the ship-shaped magnetic guide shoe through a sealing ring in the sealing groove; a target pressing ring made of a magnetic conductive material and pressing the sputtering target against the copper target backing plate by magnetic force; the interface flange is fixed on one side of the ship-shaped magnetic guide shoe and provided with a water inlet pipe and a water outlet pipe, and the water inlet pipe and the water outlet pipe are communicated into the sinking groove;

the magnetic field source of the plane magnetron sputtering source consists of a ship-shaped magnetic guide shoe, central magnetic steel which is arranged in the center of a ship-shaped magnetic guide shoe sinking groove and has the same polarity and a magnetic guide target pressing ring which is arranged at the top of the ship edge of the ship-shaped magnetic guide shoe, wherein the magnetic line of force of the magnetic field source is guided to the ship edge from the lower magnetic pole of the central magnetic steel through the ship-shaped magnetic guide shoe and then returns to the upper magnetic pole of the central magnetic steel through a gap between the magnetic guide target pressing ring and the top of the central magnetic steel;

the plane magnetron sputtering source is provided with a water-cooling cavity, the water-cooling cavity is composed of a sunken groove of the ship-shaped magnetic guide shoe and a copper target back plate which is hermetically arranged on the ship edge of the ship-shaped magnetic guide shoe through a sealing ring, and cooling water in the water-cooling cavity flows into the sunken groove of the ship-shaped magnetic guide shoe from a water inlet pipe of the interface flange and flows out of the interface flange from a water outlet pipe.

2. The planar magnetron sputtering source of claim 1 wherein the central alnico is a single permanent alnico or a row of permanent alnicos formed by splicing a group of alnicos with the same polarity in the same direction, and the alnico material is one of neodymium iron boron alnico, samarium cobalt alnico, or ferrite alnico.

3. The planar magnetron sputtering source of claim 1 wherein the boat-shaped magnetically conductive pole piece is made of one of ferritic stainless steel, martensitic stainless steel, or low carbon steel or pure iron that has been subjected to a protective treatment such as electroplating, and is in the shape of one of a circle, an ellipse, a square, or a rectangle.

4. The planar magnetron sputter source of claim 1, wherein said sputter target is one of a circular, oval, square or rectangular planar target of one of a metal, alloy or ceramic material disposed on said copper target backing plate by a thermally conductive medium.

5. The planar magnetron sputter source of claim 1 wherein the target retaining ring is an annular retaining ring made of mild steel or magnetically permeable stainless steel for retaining the sputter target against the copper target backing plate by the magnetic force of the magnetic field source and having a countersink corresponding to the shape of the sputter target.

6. The planar magnetron sputtering source of claim 4 wherein the heat conducting medium is one of a heat conducting silicone grease, indium, tin or indium tin alloy.