Metal liftoff tools and methods
AssigneeMEI, Inc.
InventorScott Tice
Life of this patent
Estimating the term…
Abstract
In certain embodiments the metal liftoff tool comprises an immersion tank for receiving a wafer cassette with wafers therein, the immersion tank including an inner weir, a lifting and lowering mechanism capable of raising and lowering the wafer cassette while submerged in fluid in the immersion tank, low pressure high velocity primary spray jets for stripping the metal, the primary spray jets positioned at opposing sides of the immersion tank parallel to the wafer surfaces planes, and secondary spray jets for pressure equalization force, positioned at the bottom of the immersion tank. A wafer lift insert is positioned at the bottom of the immersion tank to receive and periodically lift the wafers within the cassette.
Claims18
A method comprising:
- performing metal liftoff from a wafer surface by the steps of
- a. immersing a cassette of wafers in a working fluid in an immersion tank, the immersion tank having opposing first and second sidewalls and a bottom;
- b. directing working fluid streams from primary fluid spray jets positioned along at least one sidewall of the immersion tank directly toward the surfaces of the wafers, such that the working fluid stream flows over surfaces of the wafers in the cassette while immersed in the working fluid;
- c. simultaneously to directing working fluid streams from primary fluid spray jets, raising and lowering the cassette of wafers within the immersion tank through the primary fluid spray jets;
- and
- d. directing working fluid streams from secondary fluid spray jets positioned at the bottom of the immersion tank such that working fluid streams flow directly in an upward direction relative to the bottom of the immersion tank.
A method comprising:
- etching metal from a wafer surface by the steps of
- a. immersing a cassette of wafers in a working fluid in an immersion tank, the immersion tank having opposing first and second sidewalls and a bottom;
- b. directing working fluid streams from primary fluid spray jets positioned along at least one sidewall of the immersion tank directly toward the surfaces of the wafers, such that the working fluid stream flows over surfaces of the wafers in the cassette while immersed in the working fluid;
- c. simultaneously to directing working fluid streams from primary fluid spray jets, raising and lowering the cassette of wafers within the immersion tank through the primary fluid spray jets;
- d. directing working fluid streams from secondary fluid spray jets positioned at the bottom of the immersion tank such that working fluid streams flow in an upward direction relative to the bottom of the immersion tank;
- and
- e. intermittently lowering the cassette of wafers onto a submerged static lifting assembly to periodically lift the wafers off a lower portion of the cassette while working fluid streams are sprayed by the primary and/or secondary fluid spray jets.
A method comprising:
- removing layers from a wafer surface by
- a. immersing a cassette of wafers in a working fluid in an immersion tank, the immersion tank having opposing first and second sidewalls and a bottom;
- b. directing working fluid streams from primary fluid spray jets positioned along at least one sidewall of the immersion tank directly toward the surfaces of the wafers, such that the working fluid stream flows over surfaces of the wafers in the cassette while immersed in the working fluid;
- c. simultaneously to directing working fluid streams from primary fluid spray jets, raising and lowering the cassette of wafers within the immersion tank through the primary fluid spray jets;
- and
- d. directing working fluid streams from secondary fluid spray jets positioned at the bottom of the immersion tank such that working fluid streams flow in an upward direction relative to the bottom of the immersion tank while the working fluid streams are simultaneously flowing from the primary fluid spray jets.
Dependencies are inferred from the claim text.