Nano-size particles in CMP Waste

A quick run through the periodic table suggests a number of  materials you might expect in (current &) future CMP waste streams, mostly oxides, of:

Abrasives: Mn, Zr

Removed wafer material: As, Ba, Cu, Ga, Hf, Ir, La, Pt, Ru, Sb, Sr, Ta, Ti, W, Zn

I'm sure I missed a few. As device structures evolve to new functions and design concepts below 32nm, you can expect the list to continue to grow.

Indeed, as Mike (#1) expresses, the list will continue to grow. These days, it seems that every major IC fab industry keynote address has to include one slide with the periodic table of the elements showing the use of new elements with each new node.

The official Intel Corporate microprocessor blog site contains the following image (along with the sobering statistic that over 1/2 of the table is already in use):

As well all know, despite the challenges of integrating new materials, "planar" CMOS transistors (that aren't very planar anymore, but the name remains...) have continued on with new materials, instead of moving to finFETs or buried-dual-gate or other fundamentally new device structures.

In terms of managing waste-streams, the only aspect of this that seems NOT terrifying is that many of these new materials will be used in one- to few-atomic-layer films such that we may be able to ignore them as "chemical noise" (e.g., La cap oxide used as part of a CMOS HKMG flow).

Regarding #2

From CMP abrasive perspective, other than the typical suspects such as silica, ceria and alumina, one particular trend that needs to be mentioned is the emergence of slurries based on composite particles such as polymer core-metal oxide shell. Although the design approach for such composite particles is to ensure particle does not break/dissociate during CMP, but the waste stream for such abrasive system needs to be analyzed to validate such assumption

We're now (January 20th, 2010) past the official ending (the 18th) of this virtual roundtable discussion, after 4695 views of 129 replies to 18 questions. I'll edit together Interesting discussions from most of the topics into a summary document that will be posted to the Planarization Lounge.

We'll leave the topic posting open in case there are  additional comments...but they would not be included in the summary.

Happy planarizing.