SEMI International Standards
SEMI New Activity Report Form (SNARF)

Activity Number: 5410
SNARF for: New Standard: Guide for Metrology Techniques to be used in Measurement of Geometrical Parameters of Through-Silicon Vias (TSVs) in 3DS-IC Structures

Originating Global Technical Committee: 3DS-IC
Originating Technical Committee Region: North America
Task Force in which work is to be carried out: 3DS-IC Inspection and Metrology

1. Rationale: This Guide will assist the user in selection and use of TSV metrology tools, as well as a protocol for performing TSV measurements of geometrical parameters of an individual TSV, or of an array of TSV’s, such as pitch, top CD, top diameter, top area, depth, taper (or sidewall angle), bottom area, bottom CD, bottom diameter, and possibly others (e.g. scalloping and overall tilt). This guide will address the various metrology techniques that are currently available that enable TSV measurements used for 3DS-IC packaging. New TSV dimensions with higher aspect ratios and smaller diameters may challenge TSV metrology techniques. The Guide will provide examples of measurements in TSV’s at different aspect ratios, TSV measurement limits for a variety of metrology tools, the relative levels of substrate interaction, and recommendations by application. Subsequently this guide can assist producers and users of TSV metrology to develop products and conduct meaningful evaluations.
Rate the Estimated Effect on the Industry
2: Major effect on an industry sector - identify the relevant sector

Rate the Estimated Technical Difficulty of the Activity
II: Some Difficulty - Disagreements on known requirements exist but developing consensus is possible

2. Scope:
a: Define the areas to be covered or addressed by this activity or document:
A number of technologies have been developed to measure TSV’s including (but not limited to) SEM (cross-section or FIB), backside IR interferometry, front-side white light interferometry, optical microscopy, IR confocal microscopy, model-based IR, and through-focus scanning optical microscopy (TSOM). These technologies each have unique strengths and weaknesses. Some measure the wafer from the front-side and others from the back-side; some techniques are in-line and others are destructive. In this activity, we will provide examples of the capabilities of these technologies and prepare a guide to the use and applicability of these tools for different TSV measurement applications (aspect ratios). Recent studies and reports conducted at SEMATECH will be used as part of this guide.

The proposed guideline will provide guidance on key dimensional metrics related to TSV metrology techniques including the various technologies that are used, along with any limitations and/or issues and needs particular to that technology. The guide will also include applicable ranges for valid measurements where possible.

b: Expected result of activity
New Standard

3. Projected Timetable for Completion:
a: General Milestones
a. Activity Start: 04/03/2012b. 1st Draft by: 09/01/2012
c. Preballot by: d. Technical Ballot by: 01/01/2013
e. Committee Approval By:04/01/2013

Safety Considerations:
The resulting document is expected NOT to be a Safety Guideline

Intellectual Property Considerations:
a. In complying with the standard or safety guideline to be developed, the use of patented technology or a copyrighted item(s) is NOT required
b. The body of the standard and any appendices or related information sections will NOT include copyrighted material

Comments, Special Circumstances: None.

Approval: Activity approved by Committee/GCS on April 3, 2012