Pallab’s Place

As semiconductor processes get smaller, the focus has been on patterning methods for realizing these devices on the wafer.  This is not the only challenge that is facing the cutting edge of the semi industry.  An equal issue is the metrology to determine if these patterns are created properly.

Wafer metrology deals with the measurement of planarity issues, etched structure size and uniformity along with both vertical and horizontal aspects of deposited and grown layers.  A number of these steps are optical in nature and the inspection of the wafers should not exceed the time taken to create the patterns.  As a result, the same issues, variability and uncertainty that plagues litho, also plagues metrology.

At the Semicon event this year, a number of companies were showing new solutions based on particle beam technology and other techniques.  The other techniques include Photomask Metrology, SEM, Optical Linescale, and Atomic Force Microscopy and Nanoparticle Manipulation Metrology.  To help the industrial sector NIST, has also been working on this area creating references against which methods can both be calibrated and measured.

One of the biggest issues with current metrology is identifying non-destructive and non-invasive techniques for measuring in-silicon properties such as strained channels, STI, and other “engineered materials” steps that are mainstream in today’s processes.  These metrology methods are key to the continuing trend toward outsourced manufacturing, as it is the methrics upon which the wafers are sold, rather than on a functioning die basis.

Companies with major announcement in this area at the event included Nanometrics and KLA.

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Semi (www.semi.org), the group behind Semicon, has had a long history of supporting the semiconductor ecosystem – materials, equipment, test and manufacturing.  The majority of the past 4 decades the organization has focused on mainstream semiconductor circuits in Silicon and GaAs.  The large diversity of fabs that were owned and variation in process methods, made for a very large ecosystem.

Over the years the foundry model has moved into play, and there are only a few very large IDMs with new fabs, so the mainstream semiconductor manufacturing core is dramatically reduced in number.  However, Semi and the Semicon show have adapted.

This years show, not only embraced, but featured the following high growth areas, each of which requires specialty materials and equipment to product semiconductor products.  The biggest area of growth is Photovoltaics (PV) which, with the co-location of the Intersolar conference features an equal number of attendees and more exhibitors than Semicon.  Other fast growth areas include LEDs and Lighting, Flat Panel Displays (FPD), Micro-electromechanical systems (MEMS), Printed / organic / flexible electronics and related areas of in-manufacturing metrology & test along with packaging and finished product test.

LEDs (and generalized silicon photonics), FPD, and MEMS have long been staples of the semiconductor industry, but in the past, they were relegated to private shows in thier own niche ecosystem.  The direction of stacked die and 3D Ics is driving the mixed technology end products, which now need to keep these altenate technologies in the main ecosystem.  The need to keep them in the main flow is it insure the quality benefits, processing benefits and logistics benefits that have been made for CMOS are available in these technologies.

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