For more than half a century, the modern world has been built upon a single, unassuming element: silicon. It is the bedrock of the digital revolution, the silent engine inside our smartphones, laptops, data centers, and cars. This relentless march of computing power, propelling humanity from the room-sized mainframes of the 1960s to today’s small supercomputers, has relied on a remarkably accurate prediction made in 1965 by Intel co-founder Gordon Moore.
Moore’s Law prophesied that the number of transistors packed into a microchip would double roughly every two years, giving us exponentially faster and cheaper gadgets. For decades, this held true. However, by the early 2000s, this historic run began hitting a brick wall. Today, we are fighting a losing war against the laws of physics, pushing us out of the era of simple shrinking and directly into a new dawn: the ‘More than Moore’ era. The journey to our modern microchips began unexpectedly. In 1833, British scientist Michael Faraday noticed something odd: the electrical conductivity of silver sulfide increased as it got hotter.
This was completely opposite to normal metals like copper, which conduct worse when heated. By the mid-1890s, Indian polymath Acharya Jagadish Chandra Bose turned this quirky physics into reality, using lead sulfide crystals and a fine metal wire to detect radio waves. These early setups, nicknamed ‘cat’s-whisker’ detectors because of the delicate metal probe resting on the crystal, became the world’s first primitive semiconductor devices. By the 1930s, quantum physics explained why these materials behaved so strangely, proving that adding tiny amounts of impurities, a process called doping, could unlock incredible control over electricity. This spark led scientists at Bell Laboratories, USA, to seek a rugged, solid-state replacement for the fragile, hot vacuum tubes of early electronics.
The breakthrough came in 1947 with the Nobel prize-winning invention of the transistor by John Bardeen, Walter Brattain, and William Shockley. While the very first version used germanium, the industry quickly pivoted to silicon because it handled heat far better. By 1960, engineers invented the MOSFET, the basic ON/OFF switch used in chips today. Soon after, Robert Noyce created the monolithic Integrated Circuit (IC), placing multiple transistors on a single piece of silicon and connecting them with aluminum tracks. Microscopic computing was born.
For a long time, chip design felt like a magic trick. Thanks to guidelines known as Dennard Scaling, shrinking a transistor naturally made it faster, packed it more tightly, and lowered its power consumption. It was a physical free lunch that fuelled the tech boom of the 1980s and 1990s. Then came 2005. As features shrank below 100 nanometers, the free lunch abruptly ended. To make a transistor smaller, its insulating walls have to become incredibly thin. When these walls dropped down to just a few atoms thick, quantum mechanics took over. Electrons began behaving like waves rather than particles, literally ghosting or tunneling straight through the closed insulating barriers.
This caused massive power leakage, meaning your phone battery would drain even when the screen was completely off. At the same time, chips hit the Power Wall. Because there is a fundamental thermodynamic limit to how low we can drop the operating voltage without blurring the line between a digital “0” and “1,” smaller chips began generating terrifying amounts of heat. If left unchecked, modern microprocessors would generate as much heat per square centimeter as a nuclear reactor core.
To prevent chips from literally melting, manufacturers had to stall clock speeds at around 3 to 5 GHz. This brought about the era of ‘Dark Silicon’, where massive sections of a modern processor’s brain must stay completely powered off at any given moment just to keep the device from overheating. Compounding the problem is how we move data. Transistors are connected by miles of microscopic copper wires. As these wires shrink, their pathways become so narrow that electrons begin crashing into the walls and grain boundaries of the metal. Instead of flowing smoothly, they encounter massive resistance. Today, over 50 per cent of the power consumed by a high-performance computer chip is entirely wasted just pushing signals through these agonizingly tight copper traffic jams, long before any actual computing happens.
Faced with these hard physical boundaries, the semiconductor industry has shifted its strategy. If we cannot make transistors any smaller, we have to make them smarter. We are now living in the ‘More than Moore’ era, focusing on architectural cleverness and diverse materials rather than raw miniaturization. First, engineers went 3D. Instead of flat, planar designs, the industry moved to FinFETs and Nanosheets, wrapping the control gate entirely around the silicon channel to get a firmer electrostatic grip on runaway electrons. However, building these atomic-scale structures is so incredibly complex that constructing a single state-of-the-art manufacturing plant now costs over $20 billion.
Second, the industry abandoned the idea of the single, giant chip. Instead, they use Chiplets. Designers break a system down into smaller functional puzzle pieces, like a dedicated processing unit and a memory unit. These are made separately, sometimes using cheaper, more dependable methods, and then stitched together vertically using Through-Silicon Vias (TSVs). By stacking high-bandwidth memory directly on top of the main processor, data only travels micrometers instead of centimeters, bypassing the copper crisis. Finally, we are seeing alternative materials join the party.
Gallium Nitride (GaN) handles the intense high frequencies needed for 5G and 6G communications far better than silicon. Even more radical is the push toward co-packaged optics, which replaces copper wires with tiny beams of light, using photons instead of electrons to route data through chips with zero heat generation. As we reach the literal atomic end of the silicon grid, the global scientific community is shifting its gaze toward a vast, futuristic frontier. Massive international R&D operations are already racing to build a new breed of electronic switch that no longer relies on the simple movement of electric charge.
This is a critical pivot point for governments worldwide, including the Government of India, which is currently injecting billions of dollars into semiconductor technology through its India Semiconductor Mission (ISM). For these mega-investments to bear long-term fruit, policymakers and state agencies must look past traditional silicon and invest heavily in this Beyond-CMOS horizon. This global research pipeline is focused on four groundbreaking pillars: Spintronics and Topological Logic: Instead of pushing a sluggish ‘cloud’ of electrical charge that causes immense friction and heat, spintronics utilizes the intrinsic magnetic moment or ‘spin’ of the electron to process data.
By pairing this with Topological Insulators, exotic materials where electrons are forced to slide down a one-way street on the surface, we can achieve spin-momentum locking. This entirely prevents the backscattering that causes electrical resistance, allowing data to flip with almost zero current or heat. Steep-Slope Transistors: To break the thermodynamic heating limit of silicon, Tunnel FETs (TFETs) let electrons quantum tunnel straight through internal energy barriers rather than forcing them to energy-intensively hop over them, effectively filtering out hot, power-wasting leakage. Meanwhile, Negative Capacitance (NC-FETs) use a built-in ferroelectric layer to act as an internal voltage amplifier, fooling the transistor into feeling a much higher voltage than is actually applied, allowing it to switch on with minimal power.
Moiré-Based Twistronics: Rather than relying on rigid chemical doping, materials like bilayer graphene are stacked and rotated to highly precise ‘magic angles’. This alignment freezes electron kinetic energy, turning the material into a shape-shifting canvas that can morph from a superconductor to a metal to an insulator just by tweaking the voltage. This paves the way for reconfigurable logic: microprocessors that physically rewrite their own internal hardware wiring on the fly to perfectly optimize for specific artificial intelligence tasks.
and Topological Mott Insulators (TMI): This represents the ultimate holy grail of strongly correlated electron systems. Instead of the gradual, leaky transition of a silicon gate, a Mott switch triggers a collective electronic phase transition, where billions of electrons simultaneously decide to freeze in place. A TMI device creates a flawless switch: when turned off, the absolute Mott gap completely prevents power leakage. When turned on, protected topological edge channels open up for high-speed, friction-free data transit. Silicon will undoubtedly remain the legacy baseline of consumer electronics for years to come. However, the golden age of its unchallenged exponential growth has reached its historic, inevitable end. The future belongs to the nations and laboratories brave enough to engineer the quantum mechanics and materials of tomorrow.
(The writer is Distinguished Professor, RKMVERI, Belur)