Wafer polishing with improved backing arrangement
AssigneeSpeedFam-IPEC Corporation
InventorJoseph V. Cesna
Life of this patent
Estimating the term…
Abstract
A wafer carrier includes a porous media layer through which a pressurized fluid is injected. The porous media layer introduces lateral dispersion into the pressurized flow, thereby assuring a uniform pressure at the exit surface of the porous media layer, as when the porous media layer is located adjacent the wafer being polished. Alternatively, an inflatable bladder may be introduced between the porous media layer and the wafer, again with pressure being maintained uniform by the porous media layer.
Claims17
A wafer carrier for polishing a surface of a semiconductor wafer, comprising:
- a backing member defining a recess;
- a pressure balance assembly received in said recess and including a porous media layer having a core portion surrounded by a side wall extending between spaced-apart front and back opposed major surfaces;
- a fluid-impermeable sealant layer on said back surface;
- at least one hole communicating with said recess, defined by said pressure balance assembly and extending through said sealant layer and the back surface of the core portion of said porous media layer;
- and
- fluid coupling means coupling an external fluid source to said recess to thereby introduce a fluid into the core portion of said porous media layer through said at least one hole, with said porous media layer laterally dispersing fluid introduced through said at least one hole, so that said fluid travels toward said front surface in directions non-normal to said front surface so as to balance the fluid flow across said front surface.
An arrangement for polishing a surface of a semiconductor wafer, comprising:
- a support table having a central axis and an upper, support surface for engaging the surface of the semiconductor wafer to provide support for the semiconductor wafer;
- an annular recess defined by the support table, extending to the support surface so as to form an opening therein, between two annular support surface portions;
- a polish pad covering the support surface of the support table;
- a monitoring probe disposed in the recess and having a free end portion adjacent the semiconductor wafer to monitor the semiconductor wafer surface without interfering with the semiconductor wafer surface;
- table rotating means for rotating the support table about the central axis, with the monitoring probe supported against rotation with the table;
- and
- a wafer carrier suspended above said polish pad, to press the semiconductor wafer surface against the polish pad, comprising:
- a backing member defining a recess;
- a pressure balance assembly received in said recess and including a porous media layer having a core portion surrounded by a side wall extending between spaced-apart front and back opposed major surfaces;
- a fluid-impermeable sealant layer on said back surface;
- at least one hole communicating with said recess, defined by said pressure balance assembly and extending through said sealant layer into the core portion of said porous media layer;
- and
- fluid coupling means coupling an external fluid source to said recess to thereby introduce said fluid into the core portion of said porous media layer through said at least one hole, with said porous media layer laterally dispersing fluid through said at least one hole toward said front surface in directions non-normal to said front surface so as to balance the fluid flow across said front surface.
Dependencies are inferred from the claim text.