Semiconductors Are Amazing
Sir Isaac Newton once said, that he had achieved all that he did, by standing on the shoulders of great scientific men whose findings he built upon. The same might be said about silicon. Whereas germanium did all the work, silicon became an icon, with germanium being banished to obscurity in the periodic table.
In 2019, nearly 300 billion chips or semiconductors were sold. It’s about 40 chips to a person on the planet. Chips are classified on logic and memory. Logic chips perform operations or are the brains. Memory chips store data. Its material has electrical conductivity greater than an insulator but less than a conductor. Simply put, a semiconductor as a material uses electricity in a regulated manner as required. This regulation is achieved by controlled doping or adding impurities to silicon.
That the government is planning to incentivise setting up over 20 semiconductor design, components manufacturing and display fabrication units over the next six years, worth Rs 76,000 crore could be a great move to make India a hub for electronics. However, detailing for inviting applications for such manufacturing units would be the key.
In 2020, the semiconductor industry in the United States accounted for 47% of the global market. South Korean manufacturers are second in the world with about 20%, with companies from Japan and the European Union (EU) each accounting for 10% of the market. In a sense India will be making some baby steps, important for the Global market pie. Saankhya labs, ASM Technologies, Broadcom.inc, chiplogic technologies, CDIL and some others currently rule our country’s manufacturing space. A semiconductor company usually either manufactures silicon wafers or designs chips produced by other companies.
Such an Indian initiative should have come at least a decade earlier is the truth. That it has happened now is an opportunity. Globally, there is a shortage of semiconductor chips that has affected the production targets in almost all industries. Today there is no equipment which does not use semiconductors. From automobiles to washing machines, to entertainment equipment to digital devices to IoT, space, banking, healthcare and defence they all use semiconductors. Scientists even believe that robots evolving in future will be able to think and reason like humans for which, there are neurotransistors made out of semiconductors which mimic how brain neurons function.
The cost of a semiconductor chip fabrication company doubles every 4 years. Hence, only those manufacturers who can ‘up’ the production without delays will obviously benefit. Semiconductor manufacture is extremely technology and capital intensive. It would be an uphill task without adequate enabling provisions that support the various supply chains. Mere capital subsidies will not help as was seen in the past. Let’s understand the process to know the complexity involved.
Firstly, semiconductor devices are built up in a series of nanofabrication processes performed on the surface of substrates made from highly pure single crystal silicon called wafers, which allow advanced miniaturization required for cutting-edge devices. Though the most used material is silicon, germanium, gallium arsenide, and silicon carbide are also used to lesser extent. Whereas Hemlock Semiconductor Corporation and Okmetic are the largest manufacturers in the World, others like Saankhya Labs, ASM Technologies, Broadcom Inc. are based in India.
These silicon wafers, used as the base of semiconductors, are then cleaned to remove all contamination like ultrafine particles or oxide layers which otherwise form defects in the circuit.
This is followed by a very tricky process of sputtering and electrodeposition where layers of silicon oxide, aluminium and other metals are deposited to form micro thin films. These are the circuit materials on the wafer. Another cleaning round follows where super fine particles that may be adhering to the wafer after the film deposition are removed using nano-spray with deionized water. The wafer surface is then coated with a photosensitive chemical called resist after which the wafer is spun, causing a uniform layer of resist to be formed on its surface by centrifugal force.
Now for the most important step where the wafer is exposed to short wavelength deep ultraviolet radiation projected through a mask on which the circuit pattern is formed. Obviously, only the areas of the resist layer that are exposed to the light undergo a structural change, thereby transferring the pattern to the wafer. When the developer is sprayed onto the wafer, it dissolves the areas exposed to the light and reveals the thin film on the wafer surface. Remember there are still those remaining resist areas which are not exposed. They become the mask for the next etching process where the exposed thin film on the surface layer is dissolved using chemicals, such as hydrofluoric acid or phosphoric acid, forming the pattern. Next, for the semiconductor property to be realised, impurities, such as phosphor or boron ions, are implanted or doped in the wafers. In order to activate these doped ions, flash lamps or laser radiation is used which is again extremely critical for it needs to be instantaneous. Now the Resist has to be stripped off at a wet station that uses chemicals and by inducing a chemical reaction using gases.
Finally dicing follows, where the wafer is separated into individual chips, then connected to a metal frame or a lead frame using wire bonding and then enclosed in epoxy resin material, termed packaging.
What makes the above processes doubly challenging are the scales involved. ‘Nano’ most of the times. The environment and fabs for manufacturing are enclosed areas with strict controls for airborne contamination, humidity, and temperature. Great quality control is the key. As many as 500 steps are needed to process a wafer, since layers of material are deposited and removed for the desired patterns. Since the process is complicated, controlled and needing very high technology levels, the ROI is realised only on numbers sold and exported.
In as much as saying that our country must be there where technology matters for that is the only way to compete in the global markets, there is a flip side. A typical semiconductor fab, every month makes about 2 million integrated circuits per month. In doing so, it uses about 20 million gallons of water, which is then disposed of as waste. Is this a concern? Our universities would do well to look at alternatives. A high amount of energy too is required apart from using many toxic chemicals which can harm the environment. There is proven research that gallium, arsenic, and indium are capable of producing marked alterations in cellular gene products causing cancer.
Comfort, comes at a price. Economic strength comes at a price. One-upmanship comes at a price. We need to tread judiciously the chosen path. The Nation must set up an ecosystem for semiconductor markets to thrive. Not everything may be possible to manufacture here. The high environment risk processes must be outsourced. Collaborating with foundries, maybe local or global and assembly houses must be encouraged. Partnering with Integrated Device Managers (IDM)’s will be a good idea. Semiconductor Suppliers must be incentivised. Engaging with customers before a manufacturing unit is started and engaging in Design will be a good idea. Our manufacturers must think vertical and not develop IP blocks, but buy them if they are available.
