Wafer bonding system and method
AssigneeNikon Corporation
InventorAlton H. Phillips
Life of this patent
Estimating the term…
Abstract
A wafer bonding system and method using a combination of heat and a pneumatic force to bond two wafers held together in alignment. The wafers are heated via a non-contact, gaseous interface, thermal path between heating elements and the wafers. The pneumatic force is created by a pressure differential between a first pressure surrounding the two wafers and a second pressure, which is less than the first pressure, maintained between the two wafers.
Claims34
A wafer bonding apparatus for holding and bonding a first wafer to a second wafer in alignment;
- the wafer bonding apparatus comprising:
- a wafer clamp for holding the first wafer and the second wafer together in alignment, the wafer clamp including a first wafer clamping element that is configured to selectively retain the first wafer, and a second wafer clamping element that is configured to selectively, retain the second water;
- a first heating element configured to heat the first wafer to a bonding temperature, the first heating element being positioned adjacent to, but not in mechanical contact with, the first water clamping element;
- and
- a second heating element configured to heat the second wafer to the bonding temperature, the second heating element being positioned adjacent to, but not in mechanical contact with, the second wafer clamping element;
- a chamber that encircles the first wafer clamping element, the second wafer clamping element, the first heating element and the second heating element;
- a controller that maintains an ambient environment in the chamber at a first pressure;
- and
- a pneumatic force generator configured to generate a pneumatic force used to bond the first wafer and the second water heated to the bonding temperature, the pneumatic force generated by creating a pressure differential between the ambient environment within the chamber maintained at the first pressure while maintaining a second pressure between the first wafer and the second wafer held together in alignment by the clamp, wherein the first pressure is greater than the second pressure.
A wafer bonding apparatus for holding and bonding a first wafer to a second wafer in alignment, the first wafer and the second wafer each including a front surface that are configured to face one another during a wafer bonding procedure, and a back surface that are configured to face away from one another during the wafer bonding procedure, the wafer bonding apparatus comprising:
- a chamber;
- a controller that maintains an ambient environment in the chamber at a first pressure;
- a first wafer clamping element that is configured to selectively retain the first wafer, the first wafer clamping element being positioned in the chamber and configured such that the back surface of the first wafer is exposed to the ambient environment maintained at the first pressure;
- a second wafer clamping element that is configured to selectively retain the second wafer, the second wafer clamping element being positioned in the chamber;
- a first heating element that is configured to heat the back side of the first wafer to a bonding temperature during the wafer bonding procedure;
- and
- a pneumatic force generator that is configured to generate a pneumatic force directly on the back surface of the first wafer and the back surface of the second wafer, the pneumatic force being used to bond the first wafer and the second wafer, the pneumatic force being generated by creating a pressure differential between the ambient environment maintained at the first pressure while creating a second pressure between the first wafer and the second wafer, the second pressure being lower than the first pressure.
Dependencies are inferred from the claim text.