At every stage, engineers have had to fine-tune various elements of the manufacturing process and the chips -themselves. For example, in the late 1970s, when memory chip- makers faced the problem of limited availability of surface, they found an innovative answer to the problem. “The dilemma was,” says Pallab Chatterjee should we build skyscrapers or shomd we dig underground into the substrate and build basements and subways?” While working at Texas Instruments in the 1970s and 1980s. Chatterjee played a major role in developing reliable micro transistors and developing the ‘trenching’ technology for packing more and more of them per square centimetre. This deep sub-micron technology resulted in the capacity of memory chips leapfrogging.
Another person of Indian origin Tom Kailath, an emeritus professor of communication engineering & information theory at Stanford University in the US, developed signal processing techniques to compensate for the diffractive effects of masks. A start-up founded by him successfully commercialised Kailath’s ideas. Kailath’s contribution was an instance of the cross-fertilisation of technologies, with ideas from one field being applied to solve problems in a totally different field. Well known as a leading academic and teacher, Kailath takes great satisfaction in seeing some of his highly mathematical ideas getting commercialised in a manufacturing environment.
Another leading researcher in semi-conductor technology who has contributed to improving efficiencies is Krishna Saraswat, also at Stanford University. “When we were faced with intense competition from Japanese chipmakers in the 1980s, the Defence Advanced Research Projects Agency (DARPA), a leading financer of hi-tech projects in the US, undertook an initiative to improve fabrication efficiencies in the American semiconductor industry,” says Chatterjee. “We at Texas Instruments collaborated with Saraswat at Stanford, and the team solved the problems
If a modern-day cell phone were to be made of vacuum tubes instead of micro chips, it would be as tall as the Qutub Minar, and would need a small power plant to run it!
of efficient batch processing of silicon wafers.”
One of the ways diligent Japanese companies became more efficient than the Americans was by paying attention to ‘clean-room’ conditions. Chatterjee and Saraswat spotted it and brought about changes in manufacturing techniques that made the whole US chip industry competitive.
One of Saraswat’s main concerns today is to reduce the time taken by signals to travel between chips and even within chips. “The ‘interconnects’ between chips can become the limiting factor to chip speeds, even before problems are faced at the nano-physics level,” he explains.
Clearly, semiconductors have broken barriers of all sorts. With their low price, micro size and low power consumption, they have proved to be wonder materials.
Did India miss the electronics bus? Yes, it certainly did during 1970- 2000. There is the apocryphal story of Robert Noyce coming to Delhi and staying for two weeks in 1969-70 trying to convince the government of India that they should let Intel build a chip fab here. Not surprisingly, he was turned away!
However, later developments in chip design technology have allowed for fabrication and design to be separated. It is notable that technologists of Indian origin like Suhas Patil, Prabhu Goel, Raj Singh, Rajiv Mad- havan and Prakash Bhalerao have contributed to this separation of VLDI (very large-scale integrated) circuits’ design software from chip fabrication. Now cutting edge chips are being designed for the world in Bengaluru, Pune and Hyderabad, while they may be fabricated in South East Asia, Korea, Taiwan or China. In technological terms, if not in business terms, we seem to have caught the electronics bus at the next bus stop, since 80 per cent of the cost of the chip lies in design and testing.
IT industry veterans like F.C. Kohli are not satisfied with it. Kohli advocated developing appropriate courses in HTs and other engineering colleges to develop the human resources for high end chip design and testing since the 1980s and 1990s. Kohli emphasises that India needs to produce about 6,000 M Techs (4-5 times the current output) every year in VLSI design to reach the sophistication of Israel, which is a leading player in the field.
To sum up, if a modern-day cell phone were to be made of vacuum tubes instead of micro chips, it would be as tall as the Qutub Minar, and would need a small power plant to run it! While chips have become ubiquitous, Moore’s Law has remained a self-fulfilling prophecy even 50 years later. Not bad for an industry where the time scale is not measured in decades and centuries but in annual quarters!
♦ SHIVANAND KAN AVI is a theoretical physicist, senior journalist and author and former VP, TCS