The microelectronics research community seems to be forgetting about quite a few of their heroes. That needs to stop, asserts Joachim Burghartz.
This year, we celebrate one of the greatest inventions in electron devices: Julius Lilienfeld filed his first patent for the field effect transistor (FET) one hundred years ago. The FET is the predominant device in microelectronic chips. However, Lilienfeld’s patent was only a concept that he could never prove.
Lilienfeld, born Ukrainian and educated in Germany, moved to the US in 1921 and filed Canadian patent application 1745175 in 1925 and a US patent application in 1926. The device he described consisted of a conducting film on a glass substrate, with two adjacent planar contacts and a gate electrode in between – quite like what we now know as a FET built on a silicon-on-insulator (SOI) substrate. It took until 1959 for Khang and Atalla to demonstrate a functional metal-oxide-semiconductor (MOS) FET in 1959. So, Lilienfeld was the concept inventor and Khang and Atalla were the concept demonstrators.
During the more than 30 years separating conception and demonstration, there were several achievements by concept enablers. The most prominent one is, without a doubt, the demonstration of the first transistor by Bardeen and Brattain in 1947. They initially believed they had demonstrated Lilienfeld’s FET concept, but their manager Shockley showed that it was a bipolar device. Nevertheless, with their demonstration, the semiconductor device industry was born. So, Bardeen, Brattain and Shockley stand out as both concept enablers and business creators.
To become a viable industry and to be able to produce transistors with high yields, many more advancements were necessary. The gettering purification process introduced by Adolf Goetzberger at Shockley labs in the late 1950s was one. Surface passivation by silicon dioxide, developed by Frosch and Derick, another.
These advancements are not nearly as well-known, partly because they were made when the FET wasn’t yet in focus. Initially, that device was 100 times slower than the bipolar junction transistor, which became the first workhorse of the semiconductor industry. This started to change with the invention of CMOS by Wanlass and Sah in 1963, which came just in time to provide CMOS as a power-efficient IC technology required by the emerging wristwatch industry. So, the Japanese wristwatch pioneer Seiko may be considered the business enabler of CMOS technology.
Another business enabler as well as a business accelerator was Gordon Moore in formulating and motivating an exponential growth model for the semiconductor industry in 1965. The MOS scaling theory published by Bob Dennard’s team at IBM in 1973 allowed for a cost-efficient implementation of Moore’s Law to continue for more than fifty years.
In microelectronics, therefore, there are numerous heroes and different roles. There are Nobel laureates among them, such as Bardeen, Brattain and Shockley in 1956 and Jack Kilby in 2000 for his part of the invention of the IC. However, many others who have made seminal contributions to microelectronics tend to become forgotten.
In the past, knowing about those heroes and their hard work has been highly motivating for many of us in the semiconductor industry to go the extra mile in our professional lives. Today, the trend seems to be to go for the low-hanging fruit. It’s not fashionable to dig deep. For example, publications featuring a comprehensive scientific reference list are fewer and fewer these days, despite conveniently available digital databases. That’s like erasing our heroes from history.
Therefore, I hope we can return to the old ways and truly honor our heroes in microelectronics as well as give credit to those many less well-known enablers. The IEEE has started review periodicals in recent years just for that purpose; in 2024, the IEEE Electron Devices Reviews journal was launched. Such reviews may be written with the aim at putting prior art into perspective instead of advertising one’s own research achievements.
Working in a profession that recognizes past achievements and celebrates heroes is highly motivating and will keep us going the extra mile.
