SEMI International Standards
Task Force Organization Form (TFOF)

Task Force Name: 3DS IC Middle End Process Task Force

Global Technical Committee: 3DS-IC
Originating Technical Committee Region: Taiwan

1. Charter:

Develop the standards and define the specifications for middle-end process (MEOL) related manufacturing flow. Current Phase of Standard and Specification development focused on the middle-end process on wafers with or without TSVs, including post final metal temporary bonding, wafer thinning, TSV formation and reveal, micro-bumping, redistributed line (RDL) formation and carrier de-bond.

2. Scope:
Identify and suggest generic process flow for middle-end process.
Develop criteria for micro-bump dimensions, planarization and related. Dimensions can be determined into wafer-to-wafer level (WWL), die-to-wafer level (DWL), and die-to-die level (DDL).
Develop criteria for TSV CMP process and related. The via size, via surface roughness, post CMP Cu step height, and post CMP Cu bump planarization uniformity are a few of the related planarization criteria that will be critical to the micro bumping yield and inspection standard.
Develop standard for photo alignment mark and overlay mark. Alignment marks for patterning TSVs and stacking devices/wafers would be standardized for recognition.
Suggest wafer or die thickness variation and warpage before and after MEOL and identify thickness variation, void size, overall void percentage of temporary bonding glue layer, warpage control after temporary bonding and corresponding measure method.
Develop TSV quality criteria such as thickness uniformity, TSV depth variation, void, pattern density, TSV metal extrusion.
Research on in-process testing.

3. Formal linkages with Task Forces in other Regions:
Some of the Tasks and Aspects of the MEOL TF are related but not associated with the following TFs of NA 3DS IC and Taiwan 3DS IC:

NA 3DS IC Standard Task Force- Bonded Wafer Stack working group activities
Taiwan 3DS IC Standard Task Force - Testing working group activities

4. Approval:
Task Force formed on: 02/09/2012