Magnetron sputtering apparatus

Patent metadata

Field	Value
Publication number	US-9812302-B2
Application number	US-53151508-A
Country	US
Kind code	B2
Filing date	Mar 14, 2008
Priority date	Mar 16, 2007
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

In a magnetron sputtering apparatus configured such that a magnetic field pattern on a target surface moves with time by means of a rotary magnet group, it is to solve a problem that the failure rate of substrates to be processed becomes high upon plasma ignition or extinction, thereby providing a magnetron sputtering apparatus in which the failure rate of the substrates is smaller than conventional. In a magnetron sputtering apparatus, a plasma shielding member having a slit is disposed on an opposite side of a target with respect to a rotary magnet group. The distance between the plasma shielding member and the substrate is set shorter than the electron mean free path or the sheath width. Further, the width and the length of the slit are controlled to prevent impingement of plasma on the processing substrate. This makes it possible to reduce the failure rate of the substrates.

First claim

What is claimed is:

1. A magnetron sputtering apparatus comprising a backing plate to which a target is held facing a substrate to be processed, and a magnet disposed on a back side of said target relative to said substrate, and adapted to confine plasma on a target surface by forming a magnetic field on the target surface using said magnet, wherein:
said magnet comprises a rotary magnet group having a plurality of plate magnets arranged on outer periphery of a columnar rotary shaft facing said plate magnets' surface to a radial direction of the columnar rotary shaft such that the plate magnets are bonded to a surface of the columnar rotary shaft so as to form a plurality of helices and a fixed outer circumferential frame magnet which is arranged in parallel with the target surface around said rotary magnet group and which is magnetized in a direction perpendicular to the target surface;
a magnetic field pattern on the target surface moves with time by rotating said rotary magnet group along with said columnar rotary shaft;
said magnetron sputtering apparatus comprises a shielding member disposed on an opposite side of said target with respect to said rotary magnet group so as to cover an end portion of said target and to be spaced apart from said target, said shielding member being electrically grounded, and said shielding member extends in a direction the same as an axial direction of said columnar rotary shaft and forms a slit opening said target to said substrate; and
said substrate is placed on a substrate placing stage and, while plasma is excited on the target surface by applying a DC power, a RF power, or a DC power and a RF power simultaneously to said target, said substrate is placed under the slit, and a distance between an upper surface of said substrate or said substrate placing stage and a lower surface of said shielding member is shorter than a mean free path of electrons in said plasma at a position of said shielding member and,
said substrate moves in parallel with the target surface and is placed at a retreated position of said substrate which is other than under the slit upon plasma ignition or extinction, and a distance in a vertical direction between the upper surface of said substrate or said substrate placing stage and the lower surface of said shielding member is shorter than a mean free path of electrons at a position of said shielding member, and a distance in a parallel direction between an end portion of said substrate at a side of the slit and an end portion of said shielding member at a side of the slit is longer than the mean free path of electrons at the position of said shielding member.

2. A magnetron sputtering apparatus according to claim 1 , wherein:
said rotary magnet group is helical plate magnet groups forming a plurality of helices by helically disposing the plate magnets on said columnar rotary shaft such that the helices adjacent to each other in the axial direction of said columnar rotary shaft form mutually different magnetic poles of N-poles and S-poles on an outer side in a diameter direction of said columnar rotary shaft, and
said fixed outer circumferential frame magnet is, as seen from a target side, configured to surround said rotary magnet group and forms a magnetic pole of N-pole or S-pole on the target side.

3. A magnetron sputtering apparatus according to claim 1 , wherein at least part of said columnar rotary shaft is a paramagnetic substance.

4. A magnetron sputtering apparatus according to claim 1 , wherein a fixed outer peripheral paramagnetic member is disposed adjacent to said fixed outer circumferential frame magnet on an opposite side of said fixed outer circumferential frame magnet relative to said target.

5. A magnetron sputtering apparatus according to claim 1 , wherein said shielding member extends in the direction the same as the axial direction of said columnar rotary shaft and forms therealong the slit opening said target to said substrate and a width and a length of said slit are set so that, when said substrate is fixed and said plate magnet group is rotated at a constant frequency, a region of said substrate is shielded such that a film thickness to be formed per unit time is 80% or less of a maximum film thickness to be formed on said substrate per unit time when an end portion of said target is not shielded.

6. A magnetron sputtering apparatus according to claim 1 , wherein said rotary magnet group and said fixed outer circumferential magnet are disposed in a space surrounded by said target, a backing plate to which said target is held, and a wall surface continuously extended from the periphery of said backing plate and said space can be reduced in pressure.

7. A magnetron sputtering apparatus according to claim 6 , wherein said backing plate has a thickness smaller than an initial thickness of said target.

Assignees

• Ohmi Tadahiro
• Goto Tetsuya
• Matsuoka Takaaki
• Nat Univ Corp Tohoku Univ
• Tokyo Electron Ltd

Inventors

• Ohmi Tadahiro
• Goto Tetsuya
• Matsuoka Takaaki

Classifications

• H10P14/42

  using a gas or vapour · CPC title

• C23C14/35 Primary

  by application of a magnetic field, e.g. magnetron sputtering {(C23C14/3457 takes precedence)} · CPC title

• H01J37/3405

  Magnetron sputtering · CPC title

• H01J37/32495

  Means for protecting the vessel against plasma · CPC title

• H01J37/3455 Primary

  Movable magnets · CPC title