Method of producing a removable wafer connection and carrier for wafer support

Patent metadata

Field	Value
Publication number	US-9929035-B2
Application number	US-201314654471-A
Country	US
Kind code	B2
Filing date	Dec 19, 2013
Priority date	Dec 21, 2012
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

A relief structure is formed on a surface of a carrier provided for accommodating a wafer, which is fastened to the carrier by a removable adhesive contacting the carrier. The relief structure, which may be spatially confined to the center of the carrier, reduces the strength of adhesion between the wafer and the carrier. If the adhesive is appropriately selected and maintains the connection between the wafer and the carrier at elevated temperatures, further process steps can be performed at temperatures of typically 300° C. or more. The subsequent mechanical separation of the adhesive joint is facilitated by the relief structure on the carrier.

First claim

The invention claimed is:

1. A method of producing a removable wafer connection, comprising:
providing a wafer and a carrier having a surface provided for accommodating the wafer;
fastening the wafer to the carrier by a removable adhesive contacting the carrier; and
providing the surface of the carrier with a relief structure, before the adhesive is brought into contact with the surface of the carrier, the relief structure reducing the strength of adhesion between the wafer and the carrier,
wherein the relief structure is formed by a recess or a plurality of recesses in the surface of the carrier,
wherein the relief structure comprises a further recess or a plurality of further recesses in the surface of the carrier,
wherein the recess or each recess of the plurality of recesses having a larger volume than the further recess or any further recess of the plurality of further recesses,
wherein the recess or each recess of the plurality of recesses has a first depth, and the further recess or each recess of the plurality of further recesses has a second depth that is different from the first depth,
wherein the recess or the plurality of recesses and the further recess or the plurality of further recesses do not penetrate the carrier, and
wherein only the further recess or each recess of the plurality of further recesses is completely filled with the adhesive.

2. The method according to claim 1 , wherein a margin of the surface of the carrier is kept free from the relief structure.

3. The method according to claim 1 , wherein the relief structure is formed by at least one recess that is confined in a plane of the surface of the carrier by concentric circles or spirals.

4. The method according to claim 1 , further comprising:
selecting the adhesive to provide a stable connection between the wafer and the carrier at a temperature of at least 300° C. and to be removable after having been exposed to this temperature;
performing at least one further process step at this temperature or reaching this temperature while the wafer is connected to the carrier; and
subsequently removing the adhesive by introducing a solvent between the wafer and the carrier.

Assignees

• Ams Ag

Inventors

• Bodner Thomas
• Siegert Joerg
• Schrems Martin

Classifications

• H10P72/7422

  used to protect an active side of a device or wafer · CPC title

• H10P72/7416

  used during dicing or grinding · CPC title

• H10P72/7412

  the auxiliary support including means facilitating the separation of a device or wafer from the auxiliary support · CPC title

• H10P72/744

  Details of chemical or physical process used for separating the auxiliary support from a device or a wafer · CPC title

• H10P72/74 Primary

  using temporarily an auxiliary support · CPC title