JP2006037127A - Sputter electrode structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sputter electrode structure having a magnet mechanism in which a sputter target has a truncated-conical side view shape, and is arranged to obtain the line of magnetic force, the film thickness distribution is improved by changing the magnetic field generated by a magnet mechanism of a simple structure, and erosion of the sputter target is uniformized. <P>SOLUTION: In the sputter electrode structure, a sputter electrode which emits sputter particles to a substrate arranged in a vacuum container under the applied voltage comprises a sputter target having a truncated-conical side view shape arranged in an inclined manner to the substrate, a magnet mechanism which is provided on the back side of the sputter target to generate the line of magnetic force along the surface of the sputter target, and a magnetic field varying means to vary the magnetic field generated by the magnet mechanism. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sputter electrode structure built in a sputtering method thin film forming apparatus.

  A sputtering apparatus disclosed in Patent Document 1 holds a vacuum container having an exhaust unit, a target disposed in the vacuum container, and a substrate disposed in the vacuum container so as to face the target. A magnet holder for generating magnetic lines of force on the target, a magnet rotation / revolution mechanism for rotating and revolving the magnet mechanism, and a vertical mechanism for moving the magnet up and down. The revolving mechanism has a drive source and a plurality of gears that transmit the drive force from the drive source to the magnet mechanism, and the magnet mechanism has an annular inner magnet disposed near the target, and the annular And an annular outer magnet disposed outside the inner magnet.

  A sputtering apparatus disclosed in Patent Document 2 holds a vacuum container having an exhaust unit, a target disposed in the vacuum container, and a substrate disposed in the vacuum container so as to face the target. A substrate holder, an annular inner magnet disposed in the vicinity of the target, and an annular outer magnet disposed outside the annular inner magnet and movable in the center direction. A magnet mechanism, a driving mechanism for changing the distance between the outer magnet and the inner magnet, and a rotating mechanism for rotating the outer magnet.

  A sputtering apparatus disclosed in Patent Document 3 holds a vacuum container having an evacuation unit, a target disposed in the vacuum container, and a substrate disposed in the vacuum container so as to face the target. And a magnet mechanism having an annular inner moving magnet, a fixed magnet and an outer moving magnet for generating magnetic lines of force on the target, and a vertical drive mechanism for moving a specific annular magnet up and down among the magnets And a magnet rotation drive motor for rotating the annular magnet.

A magnetron sputtering apparatus disclosed in Patent Document 4 includes a target facing a substrate holder that holds a substrate to be deposited, and a plurality of magnets having magnetic poles facing each other in a direction perpendicular to the target surface. One or more cathodes having a cathode magnet disposed on the back side of the target so as to be rotatable about a rotation center axis extending in a direction perpendicular to the cathode is disposed in one vacuum film forming chamber. An annular magnet, which is magnetized in the direction opposite to the magnetizing direction of the outermost magnet located on the outermost circumference in the magnet, is placed outside the outermost magnet and can move in the direction perpendicular to the target surface. It is arranged in.
Japanese Unexamined Patent Publication No. 2000-282234 JP 2001-152333 A JP 2001-158961 A JP 2003-328122 A

  In the conventional sputter electrode structure, the sputter target material is required to be about 1.4 times larger in order to make the film formation distribution uniform within the film formation range of the substrate. In this case, the deepest part of the sputter plasma of the sputter target material is substantially equal to the outer dimension of the substrate, and about 80% of the sputtered particles jumped out by the sputter discharge adhere to portions other than the substrate. In recent years, the performance of semiconductors and electronic devices has been rapidly improved, and the demand for uniform film formation has been reduced from about 3% to 1% or less. Moreover, the sputtered particles adhering to other than the substrate have caused a decrease in the film forming speed, resulting in a decrease in productivity and an effective utilization rate of the sputter target material, leading to an increase in production cost.

  Therefore, in Patent Documents 1 to 4, the magnetic field generated by the magnet mechanism is changed to achieve uniform target erosion. However, the sputter target material has a truncated cone side surface shape, and follows the truncated cone side surface shape. It is very difficult to operate the magnet mechanism arranged to obtain the magnetic field lines as disclosed in the respective patent documents, and a complicated mechanism is required.

  For this reason, the present invention provides a sputter target material having a truncated cone side surface shape and having a magnet mechanism arranged so as to obtain magnetic lines of force along the truncated cone side surface shape. By changing the generated magnetic field, the film thickness distribution is improved and the erosion of the sputtering target is made uniform.

  Therefore, the sputter electrode structure according to the present invention has a truncated cone side surface that is inclined with respect to the substrate in the sputter electrode that ejects sputter particles with respect to the substrate disposed in the vacuum vessel when a voltage is applied. At least a sputter target material having a shape, a magnet mechanism that is provided behind the sputter target material and generates lines of magnetic force along the surface of the sputter target material, and a magnetic field changing means that changes the magnetic field generated by the magnet mechanism. It is to have.

  Further, the magnet mechanism is disposed behind a first annular magnet disposed behind a small-diameter portion of the truncated cone side surface shape of the sputter target material and a large-diameter portion of the sputter target material having a side surface shape of the truncated cone. It is desirable that the magnetic pole of the second annular magnet is set to be opposite to the magnetic pole of the first annular magnet.

  Further, it is desirable that the magnetic field changing means is a magnet reciprocally arranged on an extension line of the central axis of the first annular magnet of the magnet mechanism, and the central axis of the first annular magnet of the magnet mechanism. The magnet may be rotatably arranged on the extended line.

  Furthermore, the first annular magnet and the second annular magnet constituting the magnet mechanism are formed in a wave shape along a circumferential direction, and the magnetic field changing means is a rotating means for rotating the magnet mechanism. It is desirable that

  According to this invention, since the truncated cone side surface shape is used for the sputter target material, the film forming speed on the substrate can be increased, and the magnetic field on the sputter target material can be changed with a simple structure. Since the main scattering locations of sputter particles in the sputter target material (the locations where sputter particles are generated at high density) fluctuate and the scattering state of the sputter particles changes, the erosion on the sputter target material can be made uniform. The effective utilization rate of the sputtering target material can be increased.

  Embodiments of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, a sputtering apparatus 1 according to the present invention includes a vacuum vessel 2, a substrate holder 3 that is disposed in the vacuum vessel 2 and holds a substrate 4, and a sputtering device that is arranged facing the substrate 4. And at least the electrode 10.

  A vacuum pump (not shown) is connected to the vacuum vessel 2 through a vacuum exhaust port 7, and a vacuum state is formed in the internal space 40. The vacuum vessel 2 is provided with a gas injection pipe 5 which is opened and closed by a valve 6 to inject gas.

  The sputter electrode 10 has a substantially cylindrical electrode base 12 fixed to the lid portion 21 of the vacuum vessel via an insulating member 22 and a substantially truncated cone side surface fixed to the substrate side of the electrode base 12. A plate 13, a sputter target material 14 bonded to the back plate 13, a magnet mechanism 11 provided behind the back plate 13 and fixed to the electrode base 12 via a support 18, and the truncated cone At least a ground shield plate 16 provided on the small-diameter portion side of the back plate 13 having a side shape via an insulator 15 and an earth shield wall 17 surrounded by the outer periphery of the electrode base 12 are configured. The sputtering power source 8 uses direct current or high frequency power, and one electrode is connected to the sputtering target material 14 via the electrode base 12 and the back plate 13, and the other electrode is the vacuum vessel 2 and the earth shield plate 15. And to the earth shield wall 17. Further, cooling water is circulated to the sputter electrode 10 through the cooling pipes 23a and 23b in order to suppress the heat rise due to the spatter discharge.

  The magnet mechanism 11 includes a magnetic plate 11c formed in the shape of a truncated cone and a pair of annular magnets 11a and 11b provided at both ends thereof. In this embodiment, as shown in FIG. 2, the magnet 11a on the small diameter side is arranged so that the N pole is on the sputter target material 14 side and the S pole is on the magnetic plate 11c side. The magnet 11b is arranged so that the S pole is on the sputter target material 14 side and the N pole is on the magnetic plate 11c side. As a result, a magnetic field is generated on the sputter target material 14 from the small diameter portion to the large diameter portion along the sputter target material.

  In the sputter electrode 10 having the above configuration, the magnetic field fluctuation device 30 is provided on an extension line of the central axis of the magnet mechanism 11. In the first embodiment, as shown in FIG. 2, the magnetic field fluctuation device 30 includes a magnetic field fluctuation magnet 31 having an N pole disposed on the magnet mechanism 11 side, and the magnet 31 with respect to the magnets 11a and 11b. A rod 33 for reciprocating movement and a drive device 32 for moving the rod 33 up and down on the extension line are configured.

  With the above configuration, a predetermined vacuum state is formed in the internal space 40 of the vacuum vessel 2, a gas such as argon gas is introduced, and power is supplied by the sputtering power supply 8 to start sputtering discharge. At this time, by forming the sputter target material 14 in a ring shape that is inclined with respect to the substrate 4, specifically, in the shape of a truncated cone, the sputter plasma discharge is confined and most of the sputtered particles are directed toward the substrate 4. It is something that can be done.

  Further, by reciprocating the magnet 31 by the driving device 32, as shown in FIGS. 5A and 5B, the position of the deepest portion 51 of the sputter target material 14 is moved to the position of 51A or 51B. Therefore, the density distribution of sputtered particles can be changed as shown in 50A or 50B. As a result, the scattering state of the sputtered particles with respect to the substrate 4 can be changed, so that a film formation distribution of 1% or less can be achieved, and at the same time, the effective utilization rate of the sputter target material 14 can be increased three times. It is.

  In the second embodiment, as shown in FIG. 3, a rotating magnet 31 </ b> A is provided in place of the magnet 31 so as to be freely rotatable. This also makes it possible to achieve magnetic field fluctuations as shown in FIGS. 5A and 5B, and in the second embodiment, the left and right magnetic field fluctuation patterns can be made different. Specifically, the deepest part 51 moves to the large diameter part 51B on the side where the N pole of the rotating magnet 31A approaches, while the deepest part 51 moves to the small diameter part 51A on the side where the N pole moves away. Moving. Further, the rotating magnet 31A can be rotated in the radial direction of the magnet mechanism 11. Thereby, the effective utilization rate of the sputter target material 14 can be further increased.

  As shown in FIGS. 4A and 4B, the third embodiment replaces the annular magnet 11a on the small-diameter portion side and the annular magnet 11b on the large-diameter portion side with the small-diameter portion side formed in a wave shape in the circumferential direction. The annular magnet 11a ′ and the annular magnet 11b ′ on the large-diameter portion side formed in a wave shape in the circumferential direction are formed, and the magnet mechanism 11 is rotatable. Specifically, the support portion 18A of the magnet mechanism 11 is rotatably attached to a fixed portion 45 fixed to the electrode base 12 via a bearing 40, and a driving gear 41 is provided on the outer peripheral portion of the support portion 18A. And the gear 41 is engaged with a drive gear 42 that is fixed to the drive shaft 43 extending from the motor 44 to rotate the magnet mechanism 11.

  In the above configuration, since the magnets 11a 'and 11b' formed in a wave shape by rotating the magnet mechanism 11 rotate, the magnetic field fluctuates on the sputter target 14, and the same effect as the above-described embodiment is obtained. It is.

It is a schematic block diagram of the sputtering device which concerns on this invention. It is a schematic explanatory drawing of Example 1 of this invention. It is a schematic explanatory drawing of Example 2 of this invention. It is a schematic explanatory drawing of Example 3 of this invention. It is explanatory drawing about the effect | action of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sputtering device 2 Vacuum container 3 Substrate holder 4 Substrate 8 Sputtering power supply 10 Sputtering power supply 11 Magnet mechanism 14 Sputter target material 30 Magnetic field fluctuation device

Claims (5)

In the sputter electrode for applying sputtered particles to the substrate placed in the vacuum vessel when voltage is applied,
A sputter target material having a truncated cone side surface shape inclined with respect to the substrate;
A magnet mechanism that is provided behind the sputter target material and generates lines of magnetic force along the surface of the sputter target material;
A sputter electrode structure comprising at least magnetic field changing means for changing a magnetic field generated by the magnet mechanism.   The magnet mechanism includes a first annular magnet disposed behind a small-diameter portion of the truncated cone side surface shape of the sputter target material, and a first annular magnet disposed behind the large-diameter portion of the truncated cone side surface shape of the sputter target material. 2. The sputter electrode structure according to claim 1, wherein the sputter electrode structure is configured by two annular magnets, and a magnetic pole of the second annular magnet is set to be opposite to a magnetic pole of the first annular magnet.   The sputter electrode structure according to claim 1 or 2, wherein the magnetic field changing means is a magnet reciprocally arranged on an extension line of a central axis of the first annular magnet of the magnet mechanism.   The sputter electrode structure according to claim 1 or 2, wherein the magnetic field changing means is a magnet rotatably arranged on an extension line of a central axis of the first annular magnet of the magnet mechanism. The first annular magnet and the second annular magnet constituting the magnet mechanism are formed in a wave shape along a circumferential direction,
The sputter electrode structure according to claim 2, wherein the magnetic field changing means is a rotating means for rotating the magnet mechanism.

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