Posts

Doping: No, not the illegal in sports kind

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The beginner's post for doping. The first thing in your mind was probably the infamous incident of Lance Armstrong being caught using performance enhancing drugs during the Tour-de-France. Using these sorts of drugs is completely banned in sports and to enforce this the World Anti-Doping Agency was founded. In the context of semiconductors; doping is one of the most useful processes invented and has been utterly crucial in shaping the digital age. Let me ask you a question, what is a semiconductor? It is a material with its conductivity value in between conductors (like copper, aluminum, and other metals) and insulators (like glass, PVC, ceramic, etc.). By definition, it seems like a pretty useless material. It is an inferior conductor and an insulator. Yet, the world runs on this stuff. Why is this the case? The main property of a semiconductor is that we can change its conductivity by either optical or thermal excitation (heating or shining a light), or by doping. It follows ...

Lithography AKA Rock Drawing

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Here begins the beginner's guide to lithography. Yes, that is what the name means if you separate ‘litho’ and ‘graphy’. Doesn’t seem that scary now does it? The name is very literal to the process conducted. The rock in question is our silicon wafer and we create patterns on it for further processing. It is a very crucial process as it directly determines the transistor density which is directly proportional to the amount of data it can process at a time. Patterns are either printed or written on the wafer. Let us go through the process step by step. Figure 1: Process of lithography. First, we coat the wafer in a liquid state compound called photoresist. As the name suggests, this compound changes its properties when light is shined on it. The wafer is then spun around for a determined time and rotations per minute to ensure uniform coating. The same way we use our handheld utensil (I don’t know what you use) to evenly coat bread with butter or jam so that we get every flavored b...

Memory Bankruptcy; the curse of corpo preorders and our willing descent into oblivion

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“Hey sorry I forgot this task, it slipped from my mind,” a perfectly normal occurrence in day-to-day life but when your computer forgets a piece of information then it becomes a DEFCON 1 situation. Your computer also has the same sort of architecture your brain uses. A signal is received, your brain searches for instructions and stores some information vital for the time being as temporary memory, then a response where you perform an action and maybe you store the action in your doubtful permanent memory. Computers work the same where some memory is volatile, as in it is lost when power is switched off, and some is non-volatile, remains even after power loss. Non-volatile memory is your solid-state drives (SSD), hard disk drives (HDD), CDs, pen drives, and SD cards. Volatile memory mostly consists of Random Access Memory (RAM). RAM is your temporary memory that is used during the process and forgotten afterward. For the purposes of this article there is no need to go into detailed work...

Semiconductor Arms Race: The New Black Gold

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Chippy-chip-chips, a very simple word to describe what is probably the single greatest interdisciplinary scientific and engineering accomplishment till date. These small things that seem like toys or actual potato chips are responsible for around, let’s see here… I would like you to just think what you are reading this post on. If you don’t mind, please open the app that records your screen time, or maybe tell me the last time you might have paid in cash, I guess if you deal in black money that shouldn’t be a problem, but for a poor student like me I have trouble thinking the last time I transacted using printed currency. Figure 1: Basic overview of various manufacturing components  Reference: Semicon Talk on YouTube Semiconductors dictate your life, around 50 percent of your day is occupied by electronic devices because it is just so convenient. I would like to eat something new, just order it, or if you feel creative enough, look up a recipe. I need ingredients for the recipe, or...

Decoding the Clean Room; more than meets the eye

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In all your time on the internet you must have come across a term called ‘semiconductor manufacturing’ or an Instagram reel telling you about the size of a microprocessor. You might have wondered in what conditions does this manufacturing occur. A nanometer is a billionth of a meter, at that point you are closer to an atom than to a dust particle. Controlling the conditions of your space becomes very crucial when working at such unimaginably small scales. So where does the magic happen? A clean room is a room that is first and foremost clean. Wow Arjun, thank you for stating the obvious we would never have figured it out. I tell you most of the stuff you see that you might think is complicated has a very obvious name. The thing that actually scares everyone are the scientists’ and physicists’ names attached to the effect/phenomenon. The dirtiest entities inside the room will be us, humans. We carry dust, dirt, grime, even our hair is enough to kill any device we may be trying to fabr...

Power Transistors: Overlooking the Essential

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Processors, 2nm, RAM, memory, and especially VLSI are the buzzwords used in every news article, every LinkedIn post, every CV, and is currently ringing in everyone’s head. This is the new IT craze. Everyone is opting for courses which focus on designing these devices after seeing the amount of compensation industry giants like Nvidia, Qualcomm, AMD, Samsung, and others are providing. Yet have we thought what goes into powering these devices?  Figure 1: A power MOSFET (IRFZ44N) (left) and a Central Processing Unit (right) You must have noticed a small thing connected to every electrical appliance called a plug. It connects to a socket which is connected to the main power supply of your house. It provides 240V RMS, 50 Hz AC supply. Now what I have just written may seem like a foreign language to some of you so let us decode it. Figure 2: MATLAB plot of AC voltage Alternating current (AC) is a form of power transmission where electrons do not flow in one direction but oscillate ...