Vacuum assembly for chemical mechanical polishing

An apparatus comprising:

• a polishing pad;
• a wafer holder disposed over the polishing pad;
• and
• a slurry dispensing arm, the slurry dispensing arm configured to provide a polishing slurry to the polishing pad;
• a vacuum assembly disposed over the polishing pad, the vacuum assembly configured to suction polishing slurry and polishing debris from the polishing pad, the vacuum assembly comprising an elongated vacuum chamber having a first cross-sectional width at a widest point when viewed in a first cross-sectional view, the vacuum assembly further comprising a bottommost surface defining a slotted opening, the slotted opening having a second cross-sectional width less than the first cross-sectional width when viewed in the first cross-sectional view, the elongated vacuum chamber width tapering substantially linearly from the first cross-sectional width to the second cross-sectional width when viewed in the first cross-sectional view;
• the vacuum assembly further including a plurality of second vacuum chambers in communication with the elongated vacuum chamber and in communication with an outlet port, each second vacuum chamber having a third cross-sectional width at a point of communication with the elongated vacuum chamber and having a fourth cross-sectional width less than the third cross-sectional width at a point of communication with the outlet port, the fourth cross-sectional width being less than the third cross-sectional width;
• and
• a vacuum line coupled to the vacuum assembly.

A chemical mechanical polishing (CMP) apparatus comprising

• a polishing pad,
• a slurry dispenser,
• a workpiece holder,
• a vacuum apparatus coupled to a suction line and having a bottommost surface and a topmost surface, the bottommost surface defining a slotted opening therein, a cavity therein, and sidewalls defining the cavity, wherein the sidewalls have a cross-sectional distance therebetween, the cross-sectional distance being at a minimum value at the slotted opening and increasing substantially continuously and linearly to a first region of the cavity, the cross-sectional distance being constant from the first region of the cavity to a top of the cavity;
• and
• a plurality of inverted funnel cavities extending from the top of the cavity to the topmost surface of the vacuum apparatus, each inverted funnel cavity of the plurality of inverted funnel cavities having a first diameter opening at the top of the cavity and having a second diameter opening at the topmost surface of the vacuum apparatus, the second diameter opening being less than the first diameter opening.