Manufacture of Chipsets

In this fast-paced modern era, a life without gadgets like smartphones, laptops, PCs etc., is unimaginable. A chipset is considered to be the brain of most electronic devices. It manages the data flow between the processor, the memory and the peripherals attached.

The latest chipsets manufactured are so powerful that they can perform any task with ease, right from the basic stuff like opening files and folders, to handling high screen refresh rates, as well as ensuring the smooth functioning of some high-end softwares like Adobe Photoshop, MATLAB etc. New-Gen Smartphone chipsets can process high-resolution images of up to 200 Megapixels.

However, all these processes consume power at high rates, which encouraged the chipset manufacturing companies to manufacture more power-efficient chipsets. Thus, the leading players of this market, namely Intel, AMD (for PC chipsets), Qualcomm, MediaTek, Huawei and Apple (for Smartphone chipsets) competed for dominance. For instance, a chipset based on 4nm (size of transistor used) fabrication technology is more power-efficient than one based on 7nm technology. These novel fabrication technologies are implemented to manufacture the latest generation chipsets.

But have you ever wondered how these tiny yet crucial components are made? Let's delve deeper into the various steps involved in its manufacturing process.

Silicon is the heart and soul in the manufacture of any semiconductor-based device, including chipsets.

● Silicon isn't available in its pure state but is instead majorly found as a compound of oxygen (silica). Sand, being the most abundant source of silica, is the raw material used to manufacture semiconductors. Along with carbon, it is heated in a furnace at high temperatures to convert silica to silicon. It is then converted into pure monocrystalline silicon balls, with only one impurity atom for every 10 million silicon atoms. The balls are fabricated in different diameters - the most common ones being 150, 200 and 300 mm wide. Next, the silicon balls are cut into paper-thin wafers using special sawing techniques. Several thousands of chips can be manufactured from a single wafer.

● In the design phase, the layout of billions of transistors is made, and the functioning of various microcontrollers and connections of individual transistors are tested using special design tools. The final blueprint is transferred to photomasks, which are used to reproduce these microscopic structures on the chips with high accuracy and precision in the subsequent stages. To achieve this, the structures have to be made in a sterile atmosphere, where no dust particle greater than 0.5 micrometres is permitted around 10 litres of air.

● Next, the surface of the wafer is oxidized in a furnace operating at 1000°C to create a non-conductive layer. Subsequently, another coating of photoresist material is applied on the top to create a light-sensitive layer. The wafer is then exposed to light through the photomask using specialized light exposure machines, like steppers. The exposed photoresist layer is stripped off via the Plasma Etching technique. The wafer is again oxidized, and a layer of electrically conductive polysilicon and photoresist material is deposited on top of it. The exposed photoresist material is stripped again, such that the polysilicon layer and the oxide layer remain intact only at the centre. This step is repeated multiple times in the following stages.

● Wafers from the above step are doped with impurity atoms like boron or phosphorus, using ion implanters to enhance the conductivity of silicon. A chemical mechanical process is used to wash off the excess layers of coated materials with micrometre accuracy.

● Finally, in the assembly stage, multiple chips are taken off from the wafer and are individually placed on a package. A quality check is done using electron microscopes at various stages of the manufacturing process, to ensure that the highest level of manufacturing standards are met. Thus, the finished product obtained is a chipset, with size ranging from a few sq. millimetres to a few sq. centimetres.

FLOW DIAGRAM OF MANUFACTURING PROCESS

With the current rate of technological advancements, the demand for chipsets is sky high due to their diverse applications in various sectors like Automobiles, Electrical and Electronics, Power, Aviation etc. This demand is not going to recede anytime soon. A global chip shortage occurred recently, and the world is still healing from it.

With time, more advanced fabrication technologies will be introduced to the market, which will further enhance the chip's efficiency and overall performance.

- SACHIN BHASKAR RAJESH