Semiconductor Manufacturing

The Magic of Moore’s Law

In 1965, Moore’s Law was an observation. By 1975 Moore’s Law had become a benchmark to which semiconductor companies strove. It provided a metric and a trend that created new industries, changed cultures, and enhanced our lives. Moore’s Law made information and communication more democratic in that the common person now has more power to influence markets, politics and culture.

Why has Moore’s Law brought such amazing technological and societal advances? I would submit that it is due to a shared vision. A global consortium of companies, universities, research institutions and governments is focused on meeting the expectations of Moore’s Law. This synergy has enabled advances that no individual or single institution could accomplish. This is, in a way, similar to President Kennedy’s vision in 1961, outlining the goal to putting a man on the moon. The institutions throughout the USA focused on the goal to put a man on the moon “before this decade is out”. The goal was accomplished in 1969. Since this was the only goal outlined, the country lost focus on space exploration for a while. Therein is the difference between Moore’s Law and the “moon shot”. The benchmark/goal was a rate of development and not an end point.

But, now, the trend is slowing and appears to be approaching the end. I had assumed that Moore’s Law would be supplanted by a new computing paradigm before it became too expensive to maintain the development rate. Instead, the industry is looking at ways to keep going. The new paradigm that the semiconductor industry is touting is termed “More than Moore”. This has a different approach than with Moore’s Law. “More-than-Moore” (MtM) is characterized by functional diversification of non-digital semiconductor-based devices. It is acknowledged that “they do not necessarily scale at the same rate” as that of digital functionality. The intent is to provide additional value by migrating non-digital functionality from system board-level to ultimately integrating with the digital functions on the chip (SoC).

The problem is that MtM, now, has no singular focus. There is a diversification of domains. Each domain intends to have its own “law of expected performance” (LEP). While Moore’s Law “digital trend” is not abandoned, it is not the primary focus. I see an industry struggling to maintain value growth in the face of mounting, unsustainable costs because of its paradigm-lock on 2D scaling. I have outlined the importance of Moore’s Law in previous articles here and here and proposed that the trend can be sustained by 3D integration. The added benefit is that MtM can be implemented more simply through heterogeneous 3D integration.

Does it Matter if Moore’s Law Dies of “Old Age”?

The cleanroom at GLOBALFOUNDRIES' Fab 1 in Dresden, Germany — The cleanroom at GLOBALFOUNDRIES’ Fab 1 in Dresden, Germany

Moore’s Law appears to be coming to the end. It is getting too expensive to double transistors, particularly at the historic rate of every two years. Does that matter? What happens if it does?

The semiconductor industry is one of the few industries that produce a product that enables the advancement of the industry. The chips that are produced are used to improve design and manufacturing for the next round of products. Under the Moore’s Law paradigm, the improved chips enabled increased performance while reducing cost. Consumers felt that they needed to upgrade their computers on a regular basis just to keep up. As a result, demand continued to climb. As Moore’s Law faltered, hardware improvements slowed. The consumer did not feel the need to upgrade as often and demand slowed. The mobile market provided a boost to chip demand, but trading computing power for mobility. That market, now, seems to have reached its apex. So, the next hope is to build more servers for Cloud applications, trying to share cost of more expensive chips and IoT to massively deploy low-end chips to leverage the economies of scale.

The problem is if the cost of the improved chips goes up, the next round cost will also go up. Instead of a downward cost spiral enabled by Moore’s Law, that spiral will turn upward. The ROI will continue to shrink for semiconductor companies and negatively impact the electronics market. This, in turn, will hurt global economies.

Whether you believe in Moore’s Law or not, its multi-decade trend has produced incredible capabilities for businesses and customers. It has enabled emerging markets and economies and has improved cultures. I contend that the cost/performance improvements in the semiconductor industry are a necessary driver for continued economic growth.

Now is the time to change semiconductor manufacturing to affect a return to the Moore’s Law trend. It is time to drive 3D integration.

The Death of Moore’s Law

For the last several years, people have predicted the end of Moore’s Law. The reasoning is that there is a limit at which one can’t shrink transistors any further. A reoccurring comment has been “You can’t divide an atom.” I had assumed that its demise would be at the hands of a new paradigm like quantum computing. Now, with Intel’s announcement that the next doubling of transistors will take 2 ½ years, it looks like it may die of old age.

I, personally, do not believe that Moore’s Law needs to die of old age. Having worked within and in support of the semiconductor industry, I believe that the scaling argument is based on a faulty assumption; that one must only use two dimensions. I also believe that the industry is finally waking up to this fact with the surge in interest in 3D integration. But it has come too late to keep the industry on the Moore’s Law curve.

I have watched as the increased cost of scaling has forced the formation of collaborative research organizations, e.g. Sematech. Chip companies have shifted market and business strategies like the fabless ecosystem. And continued M&A has resulted in massive organizations with deep pockets that make barriers to market entry by new players almost impossible. As a result, I believe that the Semiconductor industry is ripe for disruption.

When I worked at the Hughes Technology Center in the early 90’s, we were working on enabling technologies for 3D integrated circuits (3DIC). Our strategy was to freeze scaling at 0.25 micron (that’s 250 nm folks!) and build another active layer on top, doubling the circuit density. There were several technologies that we were developing to do this. For example, HRL had developed a TSV on which I was able to grow high quality silicon epitaxy. This was used to build a 3D version of a Pentium-based PC in a “cube” as demonstrator. We filed for a patent disclosure, but corporate declined to pursue. Another development was wafer bonding and thinning. We developed a scanning plasma process that flattened the device wafer while thinning it. We had a 200mm demonstrator wafer bonded to a handle wafer that was 10nm thick with +/- 1nm variation. Obviously, 10nm is not very useful, but it meant that FDSOI was comparatively easy. Our bonding technique allowed conductors and dielectrics to be bonded, simultaneously. Our university collaborator used this process to demonstrate the fabrication of a CMOS circuit by bonding NMOS and PMOS circuits. There other technologies developed that I won’t go into for lack of reader attention. But these were only steps toward the ultimate goal, which was monolithic 3D integration.

Monolithic 3D integration was not to be the stacking of processed layers, but depositing and processing layers on a continuous process. Think in terms of transistors along with other components embedded in a matrix of dielectric with interconnects routed for optimal distances. This would require different equipment and different chemistries. One enabler we were working on was atomic layer deposition (ALD). The sub-category, atomic layer epitaxy (ALE) was the process we believed would provide the embedded transistor structures. I submitted a proposal the develop ALE silicon, which was declined just prior to GM Hughes Electronics’ demise. With Hughes’ breakup, all of these technologies have fallen into disuse. I believe that it is time to resurrect some of these concepts and develop the necessary equipment and processes to revitalize Moore’s Law.

I have an initial product concept that I would like to develop that would be an enabler to control the new processes. I am interested in finding investors who would fund the startup. If you are one or know of one, please contact me.