Detailed CPU Manufacturing Process

[ToXiCRaGE]

Recently I wanted to read in details how a CPU is manufactured. From the 1st step of finding the right rock, to the final product inside your computer. Anything and everything that is involved in the process, like types of material (minerals) we can find inside a cpu, to how a wafer is being cut, to how the lithography process works (what it does), interesting facts (like what grade of gold do the manufacturers use on their connecting pins of the cpu - 2K, 6k, 10K 14K, 18K, 24K gold? - , etc., everything of that type I would like to know. Are there any sites that provide such detailed (yet not boring to read) information? I could not find any. Can someone help me with this one?

Maybe this can be one of the future articles featured on Anandtech?

Thanks all.

 

[gsethi]

i can throw some light on this thing. Although i dont know all the details, i know about transistors. That is what i am studying right now.

Usually, you start with a substrate (a n-type silicon or p-type silicon). n and p type means that there are impurities added to silicon such as Boron (for n type, i think) and Phosphorous (for p-type) to make Silicon conductive. Then you would add a layer of Silicon di-oxide and pattern it using a mask (mask depends on the type of transistor and shape you are making). Then you would add the other type of substrate (if you started with n-type, you would add p-type and vice versa) to make a gate (used to transfer electrons). Then more SiO2 (SiO2 = silicon dioxide, note: SiO2 acts like an insulator). Then you would add more metals, normally Al or Cu. depends and anneal. then pattern again and all that stuff. its a complicated process.

let me give you a link to my class website where you can have a look at the lecture notes.

http://www-inst.eecs.berkeley.edu/~ee40

Go there, click on Lectures (under Spring 2002). Then read through lectures 14 through 19. (LOL, they are a lot i guess). you will get an idea as to how resistors, transistors and Mosfets are made. CPU contains combinations of these (i think, i am not that advanced yet ). Under that home page, you can look at demos (SIMPLER) will show you step by step as to how certain stuff is made.

Hope this will help. This is a class i am currently taking at UC Berkeley so...........

 

[ToXiCRaGE]

Thanks alot gsethi . It was a nice try on your part but you just gave me a brief introduction. I think we both could use such a detailed article to dig into . Thanks for the website too, I will definately check it out (do my bachelor online hahaha). I want to know bit more than just the average Joe about CPUs - not too complicated stuff though. Questions that I have would sound something like:
- from what materials are made the transistors?
- how can they 'fit' so many of them inside the die?
- how are they connected to one another and thourough what kind os system/material?
- is a transistor just a on/off switch (like digital joystick lets say) or is it more like an analog one - in which you can apply in between settings.
- how are the transistors made?
- what shapes them/cuts them?
- are wafers a big sheet of finished"dies" that will be cut ad then used in a CPU or are wafers just pure silicon sheets in which the transistors will be cut/placed/installed?
etc. etc. and much, much more

Don't ask me why I got into this, I dont even know myself but I would like to satisfy my curiosity in a not so much scientific/technical way - 'simple' english would just do fine.

 

[Actaeon]

I'm interested

 

[Healey]

Methinks gsethi does give some details. Study his post and his lecture notes, when you know that material cold, each and every fact, then you might be in need of more detailed material. You know, the not too complicate stuff that the average Joe doesn't know...

 

[gsethi]

just study my lecture notes (lecture 14 onwards) in detail with time. Also try using the SIMPLER demo on that website (I highly recommend this while reading the notes) (Wish i had done this before my Exam 2 ). You will get all of your answers.

here's a little more brief description:

Transistors consits of mixture of different elements in layers. Silicon, Boron, Phosphorous, Aluminium, Copper, Gold.
They are very small as they are made on a scale of Nano-meter (10^-9 m or 10^-6 cm or 10^-3 mm). i think you know how small a mm is, divide it by 1000 and thats 1 nano-m.
Transistors are digital switches, not analog.
how are they connected - dont know yet....maybe i will ask my TA about that.
What cuts them ? no clue - i think laser technology. I know that they use masking to remove layers of elements deposited from a certain area. Again i highly recommend using SIMPLER.

if you think this stuff is just average and you want to go to more higher advanced stuff, the next level is EE 105 at UCB. here is a link for that class website:
www-inst.eecs.berkeley.edu/~ee105

btw, we have to make a robot work for my class now. Damn, i have to start working on it now. You know make circuits, connect different gates (use op-amps) etc etc.

 

[ToXiCRaGE]

I started to learn your class from lecture 1. This way I am getting a greater understanding from the 'basics' (let's say). Besides that stuff is interesting. Im done lesson 1 and the Logistics and binary (010100001) topics. Very interesting so far but very mind 'burning'. I am planning to go through all 20 lessons (if that is even necessary) skipping whatever I think I may not need. I will use the SIMPLER. Hmm, besides that (from what I can see) maybe we could address this with Anandtech staff and maybe we can get an 'official' Anandtech article about this stuff?? Sounds good? Maybe they know some interesting facts that are hard to find - just an idea.

Like I said ghseti did give me 'detailed' info but (sorry to say) that is not enough for me. I would like to know the whole 9 yards .

PS: I know that transistors are digital switches but can u 'turn them on' half-way (like analog devices? Or they can only be in ON or OFF positions only? Can you apply a tiny bit of current to just turn them on slightly? - get my point?

Cheers.

 

[gsethi]

no, you cannot turn the transistors in between. there is a certain threshold voltage set for each transistor. if the voltage differernce applied to the transistor is below that threshold, then it is off, if it is above, then it is on. if it is at threshold, i think that it is off (gotta check my notes for that). but no intermediate setting.

the first few lectures are about designing circuits and analyzing them, using logic gates etc etc.

lmk....how much more do you want to know. I can talk with my TA and get some info on which classes actually talk about the manufacturing of the transistors in more detail. then i can give you that info

keep studying in your free time............oh yeah, after you are done with lecture 8, make sure to take Midterm 1 (LOL), that way i can see how much you are able to understand.

thanks

 

[gsethi]

<< I am planning to go through all 20 lessons >>



there will be more lectures added on each week

 

[ToXiCRaGE]

Then wish me all the best and lots of 'endurance' cuz I think I will need it hahaha.
BTW: thanks for the link to your University page though, greatly appreciated. (Let's hope some other ppl can contribute to this issue a bit more).