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Explainers

Explainers that start from simple questions such as “What is a semiconductor?” and “What does a CPU do?”, written for readers with little background. Read a series in order to follow the path from semiconductors to computers.

Semiconductors for beginners

What a semiconductor is, transistors and chips. Start here.

  1. How to Start Learning Semiconductors: Beginner Reading OrderWhere to start with semiconductors: transistors first, then how chips are made, what chips do in products, an…12 min read
  2. What Is a Semiconductor? How Conductivity Can Be ControlledA semiconductor is a material whose conductivity can be changed hugely by tiny impurities, voltage or light. …14 min read
  3. What Is a Transistor? How a Transistor Works as a SwitchA transistor is a tiny switch that turns current on and off with an electrical signal. How a MOSFET works, wh…13 min read
  4. What Is an Integrated Circuit? IC vs Chip vs Die vs SoCAn integrated circuit (IC) puts transistors and wiring into one piece of silicon. Why it mattered, chip vs. d…13 min read
  5. What Does 2nm or 3nm Mean? Chip Process Nodes Explained"2nm" and "3nm" name chip process nodes, not a size inside the chip. Why the numbers drifted from real sizes,…13 min read
  6. What Is a Diode? How It Lets Current Flow Only One WayA diode lets current flow easily one way only. How the PN junction works, why silicon needs about 0.6–0.7 V, …15 min read
  7. What Is CMOS? How nMOS and pMOS Pairs Save PowerCMOS pairs nMOS and pMOS transistors that turn on for opposite signals. Almost no current flows while the out…14 min read
  8. What Is a GAA Transistor? Gate-All-Around NanosheetsA GAA transistor wraps its gate around every side of the channel, so tiny transistors leak less. How nanoshee…14 min read

How chips are made

The steps from sand to a finished chip, in order.

  1. How Are Chips Made? The Semiconductor Manufacturing ProcessChips are built on round silicon wafers: films, light-printed patterns and etching, repeated dozens of times.…14 min read
  2. What Is a Silicon Wafer? How Wafers Are Made, Step by StepA silicon wafer is a polished disc of single-crystal silicon that holds hundreds of chips. How it is made fro…14 min read
  3. What Is EUV Lithography? How 13.5 nm Light Prints ChipsEUV lithography prints chip patterns with 13.5 nm light. Why shorter waves print finer, why it needs mirrors,…14 min read
  4. What Is Semiconductor Packaging? How Chips Are PackagedA chip package protects the die, connects it to the circuit board and carries heat away. Learn the back-end s…15 min read
  5. What Is a Cleanroom? Why Chip Fabs Fight DustA cleanroom keeps airborne particles extremely low. Why one speck can ruin a chip, how ISO classes work, and …14 min read
  6. SEM and TEM Explained: How Electron Microscopes WorkElectron microscopes use electrons, not light, to see nm-scale detail. Why light blurs below 200 nm, how SEM …14 min read
  7. Plasma in Semiconductor Manufacturing: Etching and SheathsPlasma is gas with some electrons knocked loose. How fabs make it, why wafers don't melt, how the sheath give…15 min read
  8. What Is a Printed Circuit Board (PCB)? Layers, Vias, FR-4A printed circuit board joins parts with copper wiring on an insulating board. See FR-4, layers and vias, sol…14 min read
  9. How Are Chips Tested? Wafer Test, Final Test and Burn-InChip testing finds faulty chips before they ship. A plain guide to in-line inspection, wafer test, final test…13 min read
  10. What Is Etching in Semiconductors? Wet vs Dry ExplainedEtching removes film not covered by resist to carve circuit patterns. Wet vs dry etching, straight-down etchi…15 min read
  11. What Is Thin-Film Deposition? CVD, PVD and ALD ExplainedDeposition puts very thin films on a wafer. How CVD, PVD (sputtering) and ALD work, how they differ, and how …14 min read
  12. What Is CMP in Semiconductors? Chemical Mechanical PolishingCMP flattens wafers with chemicals, fine particles and a pad. Why chips need flat layers, how copper wiring i…14 min read
  13. Ion Implantation Explained: Dose, Depth and ImplantersHow ion implantation fires dopants like boron into silicon: implanter stages, how dose and depth are set, res…14 min read
  14. What Is Photolithography? How Chip Patterns Are PrintedPhotolithography prints chip patterns with light, usually shrinking the mask to 1/4. Its steps, positive vs n…15 min read

Chips in everyday life

How the chips in phones, memory, electric cars and cameras work.

  1. Memory vs Storage: What's the Difference? (RAM vs SSD)RAM is fast working space that empties when the power is off; storage (an SSD or flash) keeps photos and apps…13 min read
  2. What Chips Are Inside a Smartphone? The Main Chips ExplainedBesides the SoC, a phone holds memory, storage, a modem, RF filters, a power chip, sensors and NFC. Learn wha…14 min read
  3. What Is a Power Semiconductor? SiC, GaN and IGBTs ExplainedPower semiconductors convert AC and DC, change voltages and control motor speed by switching large currents f…15 min read
  4. How Do Image Sensors Work? Inside a Phone Camera SensorAn image sensor turns light into electrons, then numbers. How pixels see color, BSI and stacked sensors, CMOS…14 min read
  5. What Is a Microcontroller? Tiny Computers in Everyday ThingsA microcontroller (MCU) is a tiny computer on one chip: CPU, memory and circuits for sensors and motors. How …13 min read
  6. How Do Solar Cells Work? Light to Electricity and Its LimitsA solar cell is a large PN junction that splits the electrons and holes made by light. Why efficiency has a l…15 min read
  7. How Do LEDs Work? Turning Electricity Into Light in a ChipAn LED gives off light where electrons meet holes in a semiconductor. Why the material sets the color, why si…15 min read
  8. How Do Touchscreens Work? Capacitive Touch ExplainedA phone touchscreen senses a tiny change in stored charge as a finger nears. Capacitive vs. resistive, multi-…13 min read
  9. How Do SSDs Work? Inside NAND Flash Memory, ExplainedHow do SSDs work? NAND flash stores data as electrons in cells. SLC vs TLC vs QLC, why SSDs wear out, what TB…14 min read
  10. What Is an Analog Chip? Analog vs Digital ICs ExplainedAnalog chips handle smooth, continuous signals like sound, light and temperature as voltages. How amplifiers,…14 min read
  11. How Does GPS Work? Satellites, Timing and Your PhoneGPS locates you by timing satellite signals. See why it needs four satellites, how relativity shifts their cl…14 min read
  12. LCD vs OLED: How Phone and TV Screens Make ColorScreens mix red, green and blue subpixels. An LCD filters a backlight, while OLED pixels make their own light…15 min read
  13. How DRAM Works: Cells, Refresh and Sense AmplifiersDRAM is the memory in PCs and phones. See how it stores each bit as charge, why it rewrites itself every few …14 min read
  14. What Is MEMS? How Accelerometers and Gyroscopes WorkMEMS are tiny moving parts built into silicon with chipmaking tools. See how phone accelerometers and gyrosco…15 min read
  15. How Lithium-Ion Batteries Work: Charging, Aging and SafetyLithium ions shuttle between graphite and metal oxide electrodes. mAh vs Wh, how charging works, why batterie…15 min read
  16. What Is a Laser Diode? How It Differs From an LEDA laser diode (semiconductor laser) bounces light in a tiny chip to make aligned light that is easy to focus.…15 min read
  17. What Is GaN (Gallium Nitride)? Why GaN Chargers Are SmallGaN (gallium nitride) withstands strong electric fields and switches fast, so a GaN charger needs smaller par…14 min read
  18. What Is Silicon Carbide (SiC)? Why EV Inverters Use ItSilicon carbide (SiC) withstands about 10 times the electric field of silicon, cutting losses in EV inverters…15 min read
  19. How Wireless Charging Works: Induction, Qi and Qi2A charging pad's coil makes a changing magnetic field that drives current in your phone's coil. See why align…15 min read
  20. What Is an Inverter? DC to AC for Air Conditioners and EVsAn inverter turns DC into AC at a chosen frequency and voltage. How fast switching sets motor speed in air co…15 min read
  21. What Is USB? USB-C vs USB 3, USB4 and Power DeliveryUSB is a shared standard for connecting devices. USB-C is only the plug shape: speed (USB 2.0 to USB4) and po…14 min read
  22. How Noise Cancelling Works: Using Sound to Erase SoundNoise cancelling (ANC) plays a flipped copy of the noise a mic picks up, so the two cancel in your ear. Learn…15 min read
  23. How Are Chips Cooled? Heat Sinks, Heat Pipes and LimitsChips turn nearly all their power into heat. Learn how heat flows from die to air, thermal resistance, heat p…13 min read
  24. How AC Adapters and Chargers Work: From Wall Outlet to 5 VA charger turns AC from the outlet into DC, switches it on and off tens of thousands of times a second, and u…15 min read
  25. What Chips Are Inside an Electric Car? EV Chips ExplainedThe key EV chips are inverter power semiconductors that turn battery DC into AC. Also: battery monitor ICs, s…14 min read
  26. How Do Smartwatches Measure Heart Rate? Reading Blood FlowA smartwatch shines LED light into your wrist and counts the tiny dips in the light that bounces back. Why gr…15 min read
  27. How Power Banks Work: How Many Charges From 10,000 mAh?A power bank is a lithium-ion cell plus chips that boost and guard it. Why just over 70% of 10,000 mAh reache…16 min read
  28. What Is NFC? How Contactless Cards and Tap to Pay WorkNFC is 13.56 MHz radio that works only within a few centimeters. See how battery-free cards run on a reader's…13 min read

How computers work

From computing with 0 and 1 to CPUs, memory and the OS.

  1. How Do Computers Use Binary? Calculating with 0 and 1Computers read high and low voltages as 1 and 0 and write numbers in binary. Learn 13 = 1101, bits and bytes,…15 min read
  2. What Is a CPU? What It Does Inside Your Computer and PhoneA CPU fetches a program's instructions one by one and runs billions of them a second. What GHz and cores mean…14 min read
  3. Why Are GPUs Used for AI? Matrix Math and Memory ExplainedAI is mostly multiply-and-add matrix math. GPUs run thousands of simple units at once and feed them from fast…14 min read
  4. What Is an Operating System? What an OS Actually DoesAn operating system (OS) manages the CPU, memory and devices so many apps can share them safely. Kernel, mult…14 min read
  5. How Does CPU Cache Work? Hit Rate, Lines and LocalityCPU cache is a small, fast memory on the processor chip that copies data in 64-byte lines. Learn locality, hi…14 min read
  6. What Is an NPU? The AI Engine in Phones and PCs ExplainedAn NPU is a circuit that does AI's multiply-and-add math on little power. Learn what it does in phones and PC…14 min read
  7. What Is an FPGA? A Chip You Can Rewire After It's MadeAn FPGA is a chip whose logic can be rebuilt again and again after it is made. See how LUTs, flip-flops and s…14 min read
  8. What Is an ASIC? Custom Chips vs CPUs and FPGAs ExplainedAn ASIC is a chip built for one fixed job. Learn why it beats a CPU on speed and power, why it pays off only …14 min read
  9. How Compilers Work: From Source Code to Machine CodeA compiler translates your program into machine code the CPU can run. Follow one line through parsing, optimi…15 min read
  10. What Is a Logic Gate? AND, OR, NOT and How Gates ComputeA logic gate is a tiny circuit that returns 0 or 1 by a fixed rule. Truth tables for six gates, how CMOS buil…14 min read
  11. What Is RISC-V? The Open Instruction Set ExplainedRISC-V is an open instruction set: anyone can build a CPU for it with no license fee. See what an ISA is, how…13 min read
  12. What Is an Algorithm? Search, Sorting and Big-O ExplainedAn algorithm is a set of exact steps that always ends. Binary search finds 1 item in 1 million in 20 steps. L…15 min read
  13. What Is a Database? Tables, SQL and Indexes ExplainedA database lets many people use huge amounts of data at once, safely and fast. Learn tables and keys, SQL, wh…16 min read
  14. What Is Git? Version Control Basics and Git vs GitHubVersion control records each file change so you can go back. Learn Git commits, branches, merges and conflict…14 min read

Networks and the internet

How data gets delivered, IP addresses, Wi-Fi and HTTPS.

  1. How Is Data Sent Over the Internet? Packets and RoutersThe internet splits data into packets that routers pass along by IP address. See how a web page loads, what D…14 min read
  2. What Is an IP Address? IPv4, IPv6 and Private IPs ExplainedAn IP address is the number that tells the internet where to deliver data. Learn IPv4 and IPv6, why IPv4 ran …14 min read
  3. How Does Wi-Fi Work? Radio, Bands and Why Speeds VaryWi-Fi links your phone to your router by radio. See how data rides on radio waves, how 2.4, 5 and 6 GHz diffe…15 min read
  4. What Does HTTPS Mean? What the Padlock Does and Doesn't DoHTTPS encrypts web traffic, detects tampering and verifies the site with a certificate. How keys are shared, …14 min read
  5. How Does DNS Work? From Domain Names to IP AddressesDNS turns names like www.example.com into IP addresses. See how servers worldwide pass the query along, how c…14 min read
  6. What Is 5G? How It Differs From 4G in Speed and Latency5G is the fifth generation of mobile networks. See how it differs from 4G, why real speeds fall short of targ…13 min read
  7. TCP vs UDP: What's the Difference? Reliability vs SpeedTCP sets up a connection, checks that data arrived, resends what is lost and keeps order. UDP just sends, whi…14 min read
  8. How Does Bluetooth Work? Pairing, Hopping and BLE ExplainedBluetooth links nearby devices directly by radio. See how frequency hopping shares 2.4 GHz with Wi-Fi, classi…13 min read
  9. What Is IoT? How Everyday Things Connect to the InternetIoT links devices with sensors and tiny computers to the cloud and apps. Home and factory examples, network c…15 min read
  10. What Is Ethernet? How a Wired LAN Carries Your DataEthernet (IEEE 802.3) is the standard for wired LANs. How frames and switches deliver data, cable types, spee…14 min read
  11. What Is an API? Requests, JSON, API Keys and IntegrationAn API is the agreed way one program asks another for data or work. See weather apps, Log in with Google, JSO…14 min read
  12. How Do Web Browsers Work? What Happens After You Type a URLA browser finds the server, connects with encryption, then builds HTML, CSS and JavaScript into a page. The s…14 min read

Security and everyday IT

Encryption, passwords, the cloud and AI.

  1. How Are Passwords Cracked? Why Length and Uniqueness MatterMost passwords fall to guessing, reuse of leaked passwords and fake sites. How sites store them, why length b…12 min read
  2. What Is Cloud Computing? How the Cloud Actually WorksThe cloud means renting a provider's computers in data centers over the internet. Why firms use it, its risks…14 min read
  3. What Is Encryption? Symmetric vs Public-Key Simply ExplainedEncryption uses a public method and a secret key to make data unreadable without the key. Symmetric (AES) vs …14 min read
  4. How Do Large Language Models Work? Generative AI ExplainedLLMs write by predicting the next token, one at a time. Tokens, parameters, the 3 training stages, attention,…14 min read
  5. What Is a VPN? How the Tunnel Works and What It Can't DoA VPN wraps your traffic in an encrypted tunnel to a VPN server. How it works, work vs consumer VPNs, what it…12 min read
  6. What Is Machine Learning? How Computers Learn From DataMachine learning finds rules in examples instead of people writing them. Learn how training works, the 3 type…15 min read
  7. What Is a Data Center? Power, Cooling and PUE ExplainedA data center is a building full of servers plus power, cooling and network gear. Inside racks, UPS backup, l…15 min read
  8. What Is a Firewall? How It Allows and Blocks TrafficA firewall lets through only the traffic its rules allow at a network boundary. How rules work, stateful insp…13 min read
  9. How QR Codes Work: Error Correction and the Three SquaresA QR code stores text as black and white squares. How the three big squares, Reed–Solomon error correction an…16 min read
  10. What Is Phishing? How to Spot and Stop Fake Emails and SitesPhishing uses fake emails and texts posing as real companies to steal passwords and card numbers. Why the pad…15 min read
  11. How Do Fingerprint and Face Unlock Work on Your Phone?Phones turn your fingerprint or face into numbers and compare them in a protected area of the chip. Sensor ty…15 min read
  12. What Is Malware? Viruses, Ransomware and How to Stay SafeMalware is software made to do harm. How viruses, worms, Trojans and ransomware differ, how they get in, what…14 min read

The chip industry and the news

The background to chip stories in the news.

  1. What Is a Semiconductor Fab? Cost, Water and Power ExplainedWhat a chip fab does, why most of its cost is equipment, why it uses so much water and power, how long it tak…14 min read
  2. What Is a Semiconductor Foundry? Fabless, IDM and OSATA foundry makes chips that other companies design. Why design and manufacturing split, how fabless, IDM and O…12 min read
  3. What Is HBM? High Bandwidth Memory for AI GPUs ExplainedHBM stacks DRAM chips beside an AI GPU and moves data on 1,000+ paths at once. How it works, HBM vs. GDDR, ge…13 min read
  4. What Is a Chiplet? Why Chips Are Split Into Smaller DiesA chiplet design splits a big chip into small dies joined in one package. Why big dies cost more, the trade-o…14 min read
  5. What Is a Quantum Computer? What It Can and Can't DoA quantum computer makes wrong answers cancel out; it doesn't try every answer at once. What it may do well, …14 min read
  6. What Caused the Global Chip Shortage? 2020–2022 ExplainedThe 2020–2022 chip shortage came from a demand surge, slow-to-grow fabs, disasters and panic ordering. Why ca…12 min read
  7. What Is Moore's Law? Is It Dead? A Plain ExplanationMoore's law: transistors per chip double about every two years. Not physics, but a forecast. What Moore wrote…14 min read
  8. Semiconductor Manufacturing Equipment: Types and Key MakersThe machines that deposit, pattern, etch, clean, measure, dice and test chips: the main types, key makers, wh…14 min read
  9. What Is Silicon Photonics? How Chips Send Data With LightSilicon photonics builds light paths, modulators and detectors on silicon to carry data as light. Why light b…15 min read
  10. Beyond Scaling: Where Semiconductor Technology Goes NextWhy shrinking transistors no longer delivers easy gains, and the directions that follow: GAA, CFET and backsi…

Foundations for chips: physics, chemistry and math

The physics, chemistry and math behind chips and computers, explained from the technology side.

  1. Arrhenius Equation in Chips: Acceleration Factor ExplainedHow much faster reactions and chip wear-out run when hotter: activation energy, a worked acceleration factor,…15 min read
  2. Matrix Multiplication FLOPs (2mnk) and Arithmetic IntensityA matrix multiply takes 2mnk FLOP. Divide by bytes moved for arithmetic intensity, and see why AI waits on me…15 min read
  3. Fermi-Dirac vs Boltzmann Distribution in SemiconductorsHow the Fermi-Dirac distribution sets electron numbers in semiconductors: the Fermi level, the Boltzmann appr…15 min read
  4. Quantum Tunneling in Transistors and Flash Memory, ExplainedWhy electrons pass through thin barriers they cannot climb, why it soars as oxides thin, and how it drives ga…15 min read
  5. Dopant Diffusion in Silicon: Fick's Law and √(Dt) ExplainedWhy dopants spread in hot silicon: random jumps and Fick's law, why distance grows as √(Dt), how temperature …15 min read
  6. How CRC Works: Polynomial Division in GF(2), Step by StepCRC attaches the remainder of a 0-and-1 division so the receiver can spot errors. Work one by hand, see the X…15 min read
  7. RC Time Constant Explained: Wire Delay and Clock SpeedRC time constant: how fast a capacitor charges (63% at τ, 99% at 5τ), why wire delay grows with length square…16 min read
  8. Decibels Explained: dB, dBm and Why Engineers Use ThemA decibel counts a ratio in powers of ten: 10× the power is +10 dB, 2× is about +3 dB. Learn dBm, the 20 log …15 min read
  9. What Is a Capacitor? How It Stores Charge and What It DoesA capacitor stores charge on two metal plates with an insulator between them. How it differs from a battery, …14 min read
  10. AC vs DC Explained: Impedance, Phase and Power FactorDC flows one way; AC reverses many times a second. Why outlets use AC, RMS vs peak voltage, and how capacitor…15 min read
  11. What Is an Op-Amp? How Op-Amps and Negative Feedback WorkAn op-amp is an IC that hugely amplifies the voltage difference between two inputs. How negative feedback set…13 min read
  12. What Is a Resistor? Ohm's Law, Voltage and Current ExplainedResistance is how hard it is for current to flow. Ohm's law (V = IR), LED and voltage divider examples, heat,…15 min read