US 8,945,971 B2 · Wafer warpage reduction

Abstract

The present disclosure relates a method to mitigate wafer warpage in advanced technology manufacturing processes due to crystallization of one or more amorphous layers with asymmetrical front-surface and back-surface layer thicknesses. After deposition of one or more layers of amorphous material on a front-surface and a back-surface of the wafer in a furnace tool, the front-surface layers are patterned which thins a front layer thickness. Downstream thermal processing performed at a temperature which exceeds a crystallization threshold of the amorphous material will result in asymmetric stress between the front and back surfaces due to the asymmetrical layer thicknesses. To mitigate this effect, the amount of warpage as a function of the difference in asymmetrical layer thickness may be determined such that a front-surface deposition tool may be utilized in conjunction with the furnace tool to reduce the difference in front-surface and back-surface layer thicknesses. Other methods are also disclosed.

Claims20

Dependent claims

A method of layer deposition on a substrate, comprising:

depositing one or more first layers of amorphous material comprising a total first layer thickness on a front-surface and a back-surface of the substrate;
depositing one or more second layers of the amorphous material comprising a total second layer thickness over the first layer on the front-surface;
patterning the front-surface which thins a total thickness of the one or more first and second layers on the front-surface;
and
performing a thermal process comprising a temperature which exceeds a crystallization threshold of the amorphous material;
wherein a thickness delta between a total front-surface thickness of the patterned first and second layers remaining on the front-surface and a total back-surface thickness of the one or more first layers residing on the back surface is maintained at a value which is less than a delta threshold value, which causes a predetermined amount of asymmetric stress between the front and back surfaces resulting in a predetermined warpage of the substrate.

3 more elements

A method of epitaxial layer deposition on a substrate, comprising:

depositing one or more layers of amorphous material on front and back surfaces of the substrate within one or more furnace tools, wherein a front-surface thickness and a back-surface thickness of the amorphous material are about equal;
performing patterning steps on the one or more layers on the front-surface which reduces the front-surface thickness such that a thickness delta between the front-surface thickness and the back-surface thickness is greater than a delta threshold value which causes a predetermined amount of warpage to the substrate at a first temperature above a crystallization threshold of the amorphous material;
and
constraining all downstream thermal processes to a second temperature that is less than the crystallization threshold of the amorphous material.

1 more element

Dependencies are inferred from the claim text.

Wafer warpage reduction

Life of this patent

Wafer warpage reduction

Life of this patent

Abstract

Claims20