Patent ID: 11961757
Assignee: SCREEN HOLDINGS CO., LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 14:
15. A substrate processing apparatus comprising:
a substrate holder; and
a tubular cup surrounding said substrate holder; wherein
said substrate holder including:
a holder holding a substrate in a horizontal attitude;
a ring member in a shape of a ring surrounding a peripheral edge of the substrate held by said holder of the substrate holder as seen in plan view, said ring member located between said holder of the substrate holder and said cup, said ring member having an upper surface level with or positioned below a front surface of said substrate, an inner peripheral surface extending vertically down below from an inner peripheral edge of said upper surface, and an outer peripheral surface extending vertically down below from an outer peripheral edge of said upper surface and opposed in spaced apart relation to an inner peripheral surface of said cup; and
a rotation mechanism including a motor, said rotation mechanism rotating said holder of the substrate holder and said ring member about a rotation axis at rotation speeds different from each other and/or in rotational directions different from each other, said rotation axis being a vertical axis passing through the substrate held by said holder of the substrate holder, wherein
said rotation mechanism includes:
a shaft coupling said motor and said holder of the substrate holder to each other, and
a speed transmission coupling said shaft and said ring member rotatably relative to each other and rotating said ring member at a speed ratio to the rotation speed of said shaft,
said speed transmission includes:
an external gear coupled to said shaft and rotating together with said shaft,
an internal gear coupled to said ring member, and
a first gear part including at least one first gear provided between said external gear and said internal gear and rotating said internal gear as said external gear rotates,
said at least one first gear includes an even number of first gears, and
said even number of first gears mesh with each other in series and rotate said internal gear as said external gear rotates,
said speed transmission includes:
a second gear part provided between said external gear and said internal gear and having an odd number of second gears meshing with each other in series, said second gear part rotating said internal gear as said external gear rotates; and
a mover for moving said first gear part between a first meshing position in which said first gear part is positioned between said external gear and said internal gear and a first retracted position in which said first gear part is retracted from between said external gear and said internal gear, and moving said second gear part between a second meshing position in which said second gear part is positioned between said external gear and said internal gear and a second retracted position in which said second gear part is retracted from between said external gear and said internal gear.