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.
Claims22
A metal lift-off method comprising:
- 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, 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 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 in an upward direction relative to the bottom of the immersion tank.
A metal liftoff apparatus comprising:
- a. an immersion tank having a first and second opposing sidewalls and a bottom, the immersion tank dimensioned to receive a cassette of wafers and a working fluid;
- b. primary spray jets positioned on the first and second opposing side walls of the immersion tank;
- c. secondary spray jets positioned on the bottom of the immersion tank;
- d. a stationary lifting assembly positioned at the bottom of the immersion tank for lifting the wafers a distance from a bottom portion of the cassette while submerged in the immersion tank;
- and
- e. a lifting and lowering mechanism connectable to a cassette of wafers for raising and lowering the cassette of wafers while in the immersion tank.
Dependencies are inferred from the claim text.