Independent edge control for CMP carriers
AssigneeStrasbaugh
InventorLarry A. Spiegel
Life of this patent
Estimating the term…
Abstract
A wafer carrier for controlling the edge effect during chemical mechanical planarization. A first bladder is disposed within the retaining ring to control the height of the retaining ring relative to the bottom surface of the wafer carrier. A second bladder is disposed within the carrier such that if the pressure in the bladder is regulated, the amount of force on the edge of the wafer changes. If a polishing process would cause material near the edge of the wafer to be removed at a higher rate than from the rest of the wafer, then the pressure is regulated within the bladder to reduce the force against the edge of the wafer. By reducing the force against the edge of the wafer, material is removed from the front side of the wafer at a uniform rate.
Claims13
A wafer carrier comprising a means for securing and holding a wafer, said wafer carrier further comprising:
- a mounting plate;
- a retaining ring slidably attached to the mounting plate such that the retaining ring may move a distance along the axis of the wafer carrier independent of the mounting plate, said retaining ring having by an inner diameter and having a groove disposed within a top surface of the retaining ring;
- an inflatable bladder disposed within the groove, said inflatable bladder sized and dimensioned to substantially conform to the size and dimensions of the groove;
- and
- a membrane extending across the bottom surface of the wafer carrier, said membrane further disposed within the inner diameter of the retaining ring.
A wafer carrier comprising a housing and a means for securing and holding a wafer, said wafer carrier further comprising:
- a retaining ring;
- a mounting plate operatively attached to the housing, said mounting plate adapted to hold the wafer;
- a hoop bladder disposed within an inner diameter of the retaining ring, said hoop bladder further disposed over the edge of the wafer during polishing;
- and
- a lip seal operably coupled to the housing such that the lip seal moves independently of the retaining ring and rests against the wafer during polishing.
Dependencies are inferred from the claim text.